#!/usr/bin/env bash

year=$1

if [ $# -ne 1 ] || ! [[ $1 =~ ^[0-9]+$ ]]; then
    echo "Usage: leap.sh <year>"
    exit 1
fi

if (( year % 4 == 0 && year % 100 != 0 )) || (( year % 400 == 0 )); then
    echo "true"
else
    echo "false"
fi