diff --git a/README.md b/README.md
index 0154a65..0fe85b8 100644
--- a/README.md
+++ b/README.md
@@ -16,72 +16,72 @@ Some programs are in Jupyter (`.ipynb`) notebooks, some in `.py` files. For each
 
 |Run|Programming Examples|
 |---|--|
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Advent-2018.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FAdvent-2018.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Advent-2018.ipynb) | **[Advent of Code 2018](/blob/master/ipynb/Advent-2018.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Advent%202017.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FAdvent%202017.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Advent%202017.ipynb) | **[Advent of Code 2017](/blob/master/ipynb/Advent%202017.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Advent%20of%20Code.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FAdvent%20of%20Code.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Advent%20of%20Code.ipynb) | **[Advent of Code 2016](/blob/master/ipynb/Advent%20of%20Code.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Project%20Euler%20Utils.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FProject%20Euler%20Utils.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Project%20Euler%20Utils.ipynb) | **[Project Euler Utilities](/blob/master/ipynb/Project%20Euler%20Utils.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/PropositionalLogic.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FPropositionalLogic.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/PropositionalLogic.ipynb) | **[Translating English Sentences into Propositional Logic Statements](/blob/master/ipynb/PropositionalLogic.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Beal.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FBeal.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Beal.ipynb) | **[Beal's Conjecture Revisited](/blob/master/ipynb/Beal.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/WWW.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FWWW.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/WWW.ipynb) | **[WWW: Who Will Win (NBA Title)?](/blob/master/ipynb/WWW.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Pickleball.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FPickleball.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Pickleball.ipynb) | **[Pickleball Tournament](/blob/master/ipynb/Pickleball.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Dice%20Baseball.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FDice%20Baseball.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Dice%20Baseball.ipynb) | **[Dice Baseball](/blob/master/ipynb/Dice%20Baseball.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Life.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FLife.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Life.ipynb) | **[Conway's Game of Life](/blob/master/ipynb/Life.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Sierpinski.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FSierpinski.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Sierpinski.ipynb) | **[A Chaos Game with Triangles](/blob/master/ipynb/Sierpinski.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Maze.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FMaze.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Maze.ipynb) | **[Generating Mazes](/blob/master/ipynb/Maze.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/TwelveBalls.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FTwelveBalls.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/TwelveBalls.ipynb) | **[Weighing Twelve Balls](/blob/master/ipynb/TwelveBalls.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Cant-Stop.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FCant-Stop.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Cant-Stop.ipynb) | **[Can't Stop](/blob/master/ipynb/Cant-Stop.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Bike%20Speed%20versus%20Grade.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FBike%20Speed%20versus%20Grade.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Bike%20Speed%20versus%20Grade.ipynb) | **[Bike Speed Versus Grade](/blob/master/ipynb/Bike%20Speed%20versus%20Grade.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Orderable%20Cards.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FOrderable%20Cards.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Orderable%20Cards.ipynb) | **[Properly Ordered Card Hands](/blob/master/ipynb/Orderable%20Cards.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Electoral%20Votes.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FElectoral%20Votes.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Electoral%20Votes.ipynb) | **[Tracking Trump: Electoral Votes](/blob/master/ipynb/Electoral%20Votes.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Advent-2018.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FAdvent-2018.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Advent-2018.ipynb) | **[Advent of Code 2018](ipynb/Advent-2018.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Advent%202017.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FAdvent%202017.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Advent%202017.ipynb) | **[Advent of Code 2017](ipynb/Advent%202017.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Advent%20of%20Code.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FAdvent%20of%20Code.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Advent%20of%20Code.ipynb) | **[Advent of Code 2016](ipynb/Advent%20of%20Code.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Project%20Euler%20Utils.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FProject%20Euler%20Utils.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Project%20Euler%20Utils.ipynb) | **[Project Euler Utilities](ipynb/Project%20Euler%20Utils.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/PropositionalLogic.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FPropositionalLogic.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/PropositionalLogic.ipynb) | **[Translating English Sentences into Propositional Logic Statements](ipynb/PropositionalLogic.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Beal.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FBeal.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Beal.ipynb) | **[Beal's Conjecture Revisited](ipynb/Beal.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/WWW.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FWWW.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/WWW.ipynb) | **[WWW: Who Will Win (NBA Title)?](ipynb/WWW.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Pickleball.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FPickleball.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Pickleball.ipynb) | **[Pickleball Tournament](ipynb/Pickleball.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Dice%20Baseball.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FDice%20Baseball.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Dice%20Baseball.ipynb) | **[Dice Baseball](ipynb/Dice%20Baseball.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Life.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FLife.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Life.ipynb) | **[Conway's Game of Life](ipynb/Life.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Sierpinski.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FSierpinski.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Sierpinski.ipynb) | **[A Chaos Game with Triangles](ipynb/Sierpinski.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Maze.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FMaze.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Maze.ipynb) | **[Generating Mazes](ipynb/Maze.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/TwelveBalls.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FTwelveBalls.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/TwelveBalls.ipynb) | **[Weighing Twelve Balls](ipynb/TwelveBalls.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Cant-Stop.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FCant-Stop.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Cant-Stop.ipynb) | **[Can't Stop](ipynb/Cant-Stop.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Bike%20Speed%20versus%20Grade.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FBike%20Speed%20versus%20Grade.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Bike%20Speed%20versus%20Grade.ipynb) | **[Bike Speed Versus Grade](ipynb/Bike%20Speed%20versus%20Grade.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Orderable%20Cards.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FOrderable%20Cards.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Orderable%20Cards.ipynb) | **[Properly Ordered Card Hands](ipynb/Orderable%20Cards.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Electoral%20Votes.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FElectoral%20Votes.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Electoral%20Votes.ipynb) | **[Tracking Trump: Electoral Votes](ipynb/Electoral%20Votes.ipynb)** |
 
 |Logic and Number Puzzles|
 |--|---|
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Cheryl.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FCheryl.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Cheryl.ipynb) | **[When is Cheryl's Birthday?](/blob/master/ipynb/Cheryl.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Cheryl-and-Eve.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FCheryl-and-Eve.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Cheryl-and-Eve.ipynb) | **[When Cheryl Met Eve: A Birthday Story](/blob/master/ipynb/Cheryl-and-Eve.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/RiddlerLottery.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FRiddlerLottery.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/RiddlerLottery.ipynb) | **[Riddler Lottery](/blob/master/ipynb/RiddlerLottery.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/NightKing.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FNightKing.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/NightKing.ipynb) | **[How Many Soldiers Do You Need to Beat the Night King?](/blob/master/ipynb/NightKing.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Coin%20Flip.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FCoin%20Flip.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Coin%20Flip.ipynb) | **[The Devil and the Coin Flip Game](/blob/master/ipynb/Coin%20Flip.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Mean%20Misanthrope%20Density.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FMean%20Misanthrope%20Density.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Mean%20Misanthrope%20Density.ipynb) | **[The Puzzle of the Misanthropic Neighbors](/blob/master/ipynb/Mean%20Misanthrope%20Density.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Countdown.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FCountdown.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Countdown.ipynb) | **[Four 4s, Five 5s, and Countdown to 2016](/blob/master/ipynb/Countdown.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Sicherman%20Dice.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FSicherman%20Dice.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Sicherman%20Dice.ipynb) | **[Sicherman Dice](/blob/master/ipynb/Sicherman%20Dice.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Golomb-Puzzle.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FGolomb-Puzzle.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Golomb-Puzzle.ipynb) | **[Sol Golomb's Rectangle Puzzle](/blob/master/ipynb/Golomb-Puzzle.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Cryptarithmetic.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FCryptarithmetic.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Cryptarithmetic.ipynb) | **[Cryptarithmetic](/blob/master/ipynb/Cryptarithmetic.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Riddler%20Battle%20Royale.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FRiddler%20Battle%20Royale.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Riddler%20Battle%20Royale.ipynb) | **[The Riddler: Battle Royale](/blob/master/ipynb/Riddler%20Battle%20Royale.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Cheryl.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FCheryl.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Cheryl.ipynb) | **[When is Cheryl's Birthday?](ipynb/Cheryl.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Cheryl-and-Eve.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FCheryl-and-Eve.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Cheryl-and-Eve.ipynb) | **[When Cheryl Met Eve: A Birthday Story](ipynb/Cheryl-and-Eve.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/RiddlerLottery.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FRiddlerLottery.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/RiddlerLottery.ipynb) | **[Riddler Lottery](ipynb/RiddlerLottery.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/NightKing.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FNightKing.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/NightKing.ipynb) | **[How Many Soldiers Do You Need to Beat the Night King?](ipynb/NightKing.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Coin%20Flip.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FCoin%20Flip.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Coin%20Flip.ipynb) | **[The Devil and the Coin Flip Game](ipynb/Coin%20Flip.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Mean%20Misanthrope%20Density.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FMean%20Misanthrope%20Density.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Mean%20Misanthrope%20Density.ipynb) | **[The Puzzle of the Misanthropic Neighbors](ipynb/Mean%20Misanthrope%20Density.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Countdown.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FCountdown.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Countdown.ipynb) | **[Four 4s, Five 5s, and Countdown to 2016](ipynb/Countdown.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Sicherman%20Dice.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FSicherman%20Dice.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Sicherman%20Dice.ipynb) | **[Sicherman Dice](ipynb/Sicherman%20Dice.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Golomb-Puzzle.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FGolomb-Puzzle.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Golomb-Puzzle.ipynb) | **[Sol Golomb's Rectangle Puzzle](ipynb/Golomb-Puzzle.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Cryptarithmetic.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FCryptarithmetic.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Cryptarithmetic.ipynb) | **[Cryptarithmetic](ipynb/Cryptarithmetic.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Riddler%20Battle%20Royale.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FRiddler%20Battle%20Royale.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Riddler%20Battle%20Royale.ipynb) | **[The Riddler: Battle Royale](ipynb/Riddler%20Battle%20Royale.ipynb)** |
 
 |Run|Word Games|
 |---|--|
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/SpellingBee.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FSpellingBee.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/SpellingBee.ipynb) | **[Spelling Bee](/blob/master/ipynb/SpellingBee.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/ElementSpelling.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FElementSpelling.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/ElementSpelling.ipynb) | **[Chemical Element Spelling](/blob/master/ipynb/ElementSpelling.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Boggle.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FBoggle.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Boggle.ipynb) | **[Boggle / Inverse Boggle](/blob/master/ipynb/Boggle.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Portmantout.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FPortmantout.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Portmantout.ipynb) | **[Portmantout Words](/blob/master/ipynb/Portmantout.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/xkcd-Name-Dominoes.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2Fxkcd-Name-Dominoes.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/xkcd-Name-Dominoes.ipynb) | **[xkcd 1970: Name Dominoes](/blob/master/ipynb/xkcd-Name-Dominoes.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Ghost.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FGhost.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Ghost.ipynb) | **[Ghost](/blob/master/ipynb/Ghost.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/pal3.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2Fpal3.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/pal3.ipynb) | **[World's Longest Palindrome](/blob/master/ipynb/pal3.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Scrabble.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FScrabble.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Scrabble.ipynb) | **[Refactoring a Crossword Game Program](/blob/master/ipynb/Scrabble.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/xkcd1313.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2Fxkcd1313.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/xkcd1313.ipynb) | **[xkcd 1313: Regex Golf](/blob/master/ipynb/xkcd1313.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/xkcd1313-part2.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2Fxkcd1313-part2.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/xkcd1313-part2.ipynb) | **[xkcd 1313: Regex Golf (Part 2: Infinite Problems)](/blob/master/ipynb/xkcd1313-part2.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Fred%20Buns.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FFred%20Buns.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Fred%20Buns.ipynb) | **[Let's Code About Bike Locks](/blob/master/ipynb/Fred%20Buns.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Gesture%20Typing.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FGesture%20Typing.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Gesture%20Typing.ipynb) | **[Gesture Typing](/blob/master/ipynb/Gesture%20Typing.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/How%20to%20Do%20Things%20with%20Words.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FHow%20to%20Do%20Things%20with%20Words.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/How%20to%20Do%20Things%20with%20Words.ipynb) | **[How to Do Things with Words, or Statistical Natural Language Processing in Python](/blob/master/ipynb/How%20to%20Do%20Things%20with%20Words.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/SpellingBee.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FSpellingBee.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/SpellingBee.ipynb) | **[Spelling Bee](ipynb/SpellingBee.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/ElementSpelling.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FElementSpelling.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/ElementSpelling.ipynb) | **[Chemical Element Spelling](ipynb/ElementSpelling.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Boggle.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FBoggle.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Boggle.ipynb) | **[Boggle / Inverse Boggle](ipynb/Boggle.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Portmantout.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FPortmantout.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Portmantout.ipynb) | **[Portmantout Words](ipynb/Portmantout.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/xkcd-Name-Dominoes.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fxkcd-Name-Dominoes.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/xkcd-Name-Dominoes.ipynb) | **[xkcd 1970: Name Dominoes](ipynb/xkcd-Name-Dominoes.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Ghost.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FGhost.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Ghost.ipynb) | **[Ghost](ipynb/Ghost.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/pal3.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fpal3.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/pal3.ipynb) | **[World's Longest Palindrome](ipynb/pal3.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Scrabble.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FScrabble.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Scrabble.ipynb) | **[Refactoring a Crossword Game Program](ipynb/Scrabble.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/xkcd1313.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fxkcd1313.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/xkcd1313.ipynb) | **[xkcd 1313: Regex Golf](ipynb/xkcd1313.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/xkcd1313-part2.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2Fxkcd1313-part2.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/xkcd1313-part2.ipynb) | **[xkcd 1313: Regex Golf (Part 2: Infinite Problems)](ipynb/xkcd1313-part2.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Fred%20Buns.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FFred%20Buns.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Fred%20Buns.ipynb) | **[Let's Code About Bike Locks](ipynb/Fred%20Buns.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Gesture%20Typing.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FGesture%20Typing.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Gesture%20Typing.ipynb) | **[Gesture Typing](ipynb/Gesture%20Typing.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/How%20to%20Do%20Things%20with%20Words.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FHow%20to%20Do%20Things%20with%20Words.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/How%20to%20Do%20Things%20with%20Words.ipynb) | **[How to Do Things with Words, or Statistical Natural Language Processing in Python](ipynb/How%20to%20Do%20Things%20with%20Words.ipynb)** |
 
 |Run|Math Concepts|
 |--|--|
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Probability.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FProbability.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Probability.ipynb) | **[A Concrete Introduction to Probability](/blob/master/ipynb/Probability.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/ProbabilityParadox.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FProbabilityParadox.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/ProbabilityParadox.ipynb) | **[Probability, Paradox, and the Reasonable Person Principle](/blob/master/ipynb/ProbabilityParadox.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/ProbabilitySimulation.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FProbabilitySimulation.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/ProbabilitySimulation.ipynb) | **[Estimating Probabilities with Simulations](/blob/master/ipynb/ProbabilitySimulation.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Differentiation.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FDifferentiation.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Differentiation.ipynb) | **[Symbolic Algebra, Simplification, and Differentiation](/blob/master/ipynb/Differentiation.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Economics.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FEconomics.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Economics.ipynb) | **[Economics Simulation](/blob/master/ipynb/Economics.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/How%20To%20Count%20Things.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FHow%20To%20Count%20Things.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/How%20To%20Count%20Things.ipynb) | **[How to Count Things](/blob/master/ipynb/How%20To%20Count%20Things.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Socks.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FSocks.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Socks.ipynb) | **[Pairing Socks](/blob/master/ipynb/Socks.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Euler's%20Conjecture.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FEuler's%20Conjecture.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Euler's%20Conjecture.ipynb) | **[Euler's Sum of Powers Conjecture](/blob/master/ipynb/Euler's%20Conjecture.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Probability.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FProbability.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Probability.ipynb) | **[A Concrete Introduction to Probability](ipynb/Probability.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/ProbabilityParadox.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FProbabilityParadox.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/ProbabilityParadox.ipynb) | **[Probability, Paradox, and the Reasonable Person Principle](ipynb/ProbabilityParadox.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/ProbabilitySimulation.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FProbabilitySimulation.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/ProbabilitySimulation.ipynb) | **[Estimating Probabilities with Simulations](ipynb/ProbabilitySimulation.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Differentiation.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FDifferentiation.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Differentiation.ipynb) | **[Symbolic Algebra, Simplification, and Differentiation](ipynb/Differentiation.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Economics.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FEconomics.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Economics.ipynb) | **[Economics Simulation](ipynb/Economics.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/How%20To%20Count%20Things.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FHow%20To%20Count%20Things.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/How%20To%20Count%20Things.ipynb) | **[How to Count Things](ipynb/How%20To%20Count%20Things.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Socks.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FSocks.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Socks.ipynb) | **[Pairing Socks](ipynb/Socks.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Euler's%20Conjecture.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FEuler's%20Conjecture.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Euler's%20Conjecture.ipynb) | **[Euler's Sum of Powers Conjecture](ipynb/Euler's%20Conjecture.ipynb)** |
 
 |Run|Computer Science Algorithms and Concepts|
 |--|--|
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Convex%20Hull.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FConvex%20Hull.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Convex%20Hull.ipynb) | **[The Convex Hull Problem](/blob/master/ipynb/Convex%20Hull.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/TSP.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FTSP.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/TSP.ipynb) | **[The Traveling Salesperson Problem](/blob/master/ipynb/TSP.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/StableMatching.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FStableMatching.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/StableMatching.ipynb) | **[The Stable Matching Problem](/blob/master/ipynb/StableMatching.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/BASIC.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FBASIC.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/BASIC.ipynb) | **[BASIC Interpreter](/blob/master/ipynb/BASIC.ipynb)** |
-| [CO](https://colab.research.google.com/github/googlecolab/colabtools//blob/master/ipynb/Snobol.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2F%2Fblob%2Fmaster%2Fipynb%2FSnobol.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes//blob/master/ipynb/Snobol.ipynb) | **[Bad Grade, Good Experience](/blob/master/ipynb/Snobol.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Convex%20Hull.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FConvex%20Hull.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Convex%20Hull.ipynb) | **[The Convex Hull Problem](ipynb/Convex%20Hull.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/TSP.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FTSP.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/TSP.ipynb) | **[The Traveling Salesperson Problem](ipynb/TSP.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/StableMatching.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FStableMatching.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/StableMatching.ipynb) | **[The Stable Matching Problem](ipynb/StableMatching.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/BASIC.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FBASIC.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/BASIC.ipynb) | **[BASIC Interpreter](ipynb/BASIC.ipynb)** |
+| [CO](https://colab.research.google.com/github/googlecolab/colabtools/Snobol.ipynb) [DN](https://beta.deepnote.org/launch?template=python_3.6&url=https%3A%2F%2Fgithub.com%2Fnorvig%2Fpytudes%2FSnobol.ipynb)  [MY](https://mybinder.org/v2/gh/norvig/pytudes/master) [NB](https://nbviewer.jupyter.org/github/norvig/pytudes/Snobol.ipynb) | **[Bad Grade, Good Experience](ipynb/Snobol.ipynb)** |
 
 # Index of Python Files