same no of chips on each sqaure of 5x5 board, after many moves
Source: 2005 Peru MO (ONEM) L3 p4 - finals
November 23, 2022
combinatorics
Problem Statement
On the grid board shown, a token is placed on each white space.
https://cdn.artofproblemsolving.com/attachments/3/2/0060b2436edb0ce25160d2f94f379defef237c.png
A move consists of choosing four squares on the board that form a "" in any of the shapes shown below, and add a token to each of these four squares.
https://cdn.artofproblemsolving.com/attachments/8/c/3890aed5289ec9ea2d147f8000a0422c233029.png
Is it possible, after carrying out several moves, to get the squares to have the same amount of chips?