MathDB
APMO 2023 Problem 1

Source:

July 5, 2023
APMOAPMO 2023combinatoricscombinatorial geometry

Problem Statement

Let n5n \geq 5 be an integer. Consider nn squares with side lengths 1,2,,n1, 2, \dots , n, respectively. The squares are arranged in the plane with their sides parallel to the xx and yy axes. Suppose that no two squares touch, except possibly at their vertices. Show that it is possible to arrange these squares in a way such that every square touches exactly two other squares.