MathDB
Red Alert!

Source: INMO 2024/2

January 21, 2024
combinatorics

Problem Statement

All the squares of a 2024×20242024 \times 2024 board are coloured white. In one move, Mohit can select one row or column whose every square is white, choose exactly 10001000 squares in that row or column, and colour all of them red. Find maximum number of squares Mohit can colour in a finite number of moves.   Proposed by Pranjal Srivastava