Moscow 1996 G8 P5 - Rook on a Chess Board
Source:
May 18, 2014
Problem Statement
A rook stands in a corner of an by chess board. For what , moving alternately along horizontals and verticals, can the rook visit all the cells of the board and return to the initial corner after moves? (A cell is visited only if the rook stops on it, those that the rook “flew over” during the move are not counted as visited.) Proposed by A. Spivak