diff --git a/.gitignore b/.gitignore
index 87620ac..00dd6ea 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,4 @@
 .ipynb_checkpoints/
+venv
+.idea
+.vscode
diff --git a/hints/ex01_import_numpy.py b/hints/ex01_import_numpy.py
new file mode 100644
index 0000000..552cccb
--- /dev/null
+++ b/hints/ex01_import_numpy.py
@@ -0,0 +1 @@
+print("hint: import … as …")
diff --git a/hints/ex02_print_version_and_config.py b/hints/ex02_print_version_and_config.py
new file mode 100644
index 0000000..e69de29
diff --git a/hints/ex03_null_vect_size_10.py b/hints/ex03_null_vect_size_10.py
new file mode 100644
index 0000000..e69de29
diff --git a/hints/ex04_memory_size_of_an_array.py b/hints/ex04_memory_size_of_an_array.py
new file mode 100644
index 0000000..e69de29
diff --git a/hints/ex05_get_infos.py b/hints/ex05_get_infos.py
new file mode 100644
index 0000000..e69de29
diff --git a/requirements.txt b/requirements.txt
index 5da331c..0ad85da 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1,4 @@
-numpy
-pandas
+numpy==1.17.4
+pandas==0.25.3
+jupyter==1.0.0
+jupyterthemes==0.20.0
diff --git a/solutions/ex01_import_numpy.py b/solutions/ex01_import_numpy.py
new file mode 100644
index 0000000..a22b22b
--- /dev/null
+++ b/solutions/ex01_import_numpy.py
@@ -0,0 +1 @@
+import numpy as np
diff --git a/solutions/ex02_print_version_and_config.py b/solutions/ex02_print_version_and_config.py
new file mode 100644
index 0000000..e69de29
diff --git a/solutions/ex03_null_vect_size_10.py b/solutions/ex03_null_vect_size_10.py
new file mode 100644
index 0000000..e69de29
diff --git a/solutions/ex04_memory_size_of_an_array.py b/solutions/ex04_memory_size_of_an_array.py
new file mode 100644
index 0000000..e69de29
diff --git a/solutions/ex05_get_infos.py b/solutions/ex05_get_infos.py
new file mode 100644
index 0000000..e69de29