When a chess piece has traveled around a chessboard touching every square exactly once, it has complted a "tour" of the board.
Your task is to complete a tour on the board below using the selected chess piece. Your tour has been started on a randomly
selected square. Green squares indicate a legal move, and the numbers on each
square tell you how many open moves are available from that square. The "Warnsdorff" heuristic for finding a tour is to
always move to a square with the lowest number of available moves.