MathDB
Combinatorics in a cube

Source: Baltic Way 2016, Problem 14

November 5, 2016
combinatorics

Problem Statement

A cube consists of 434^3 unit cubes each containing an integer. At each move, you choose a unit cube and increase by 11 all the integers in the neighbouring cubes having a face in common with the chosen cube. Is it possible to reach a position where all the 434^3 integers are divisible by 3,3, no matter what the starting position is?