Bundeswettbewerb Mathematik 1978 Problem 1.1
Source: Bundeswettbewerb Mathematik 1978 Round 1
October 12, 2022
combinatoricsChessboardknightEven
Problem Statement
A knight is modified so that it moves fields horizontally or vertically and fields in the perpendicular direction. It is placed on an infinite chessboard. If the knight returns to the initial field after moves, show that must be even.