Operation on n by n grid with integers
Source: China Mathematical Olympiad 2019 Q5
November 15, 2018
combinatorics
Problem Statement
Given is an board, with an integer written in each grid. For each move, I can choose any grid, and add to all numbers in its row and column. Find the largest , such that for any initial choice of integers, I can make a finite number of moves so that there are at least even numbers on the board.