Take a set of chess pieces and throw them all away except
for one knight. Place the knight on any one of the 64 squares of a chess board.
Can you make 63 legal moves so that you visit every square
on the chess board exactly once? As a reminder, a knight can move two squares
in a straight line, followed by a ninety degree turn and a move of one further
square. It might seem like a hard task, but this set of moves, called the
knight’s tour, can be achieved in too many ways to count.