MathDB
Numbers on 100-gon

Source: 239 2009 J6

July 29, 2020
combinatorics

Problem Statement

Non-negative integers are placed on the vertices of a 100100-gon, the sum of the numbers is 9999. Every minute at one of the vertices that is equal to 00 will be replaced by 22 and both its neighboring numbers are subtracted by 11. Prove that after a while a negative number will appear on the board.