Chip on a board makes moves
Source: Assara 2024 J7
October 14, 2024
combinatorics
Problem Statement
There is a chip in one of the squares on the checkered board. In one move, she can move either square to the right, or diagonally to the left and up, or to the left and down (see Fig.). The chip made moves and returned to the starting square. Prove that a) is divisible by , b) is divisible by .
K.A.Sukhov