IMO 2017 Shortlist C1
A re tangle R with odd integer side lengths is divided into small re tangles with integer side lengths. Prove that there...
Category: Combinatorics
Problem
A re tangle R with odd integer side lengths is divided into small re tangles with integer side lengths. Prove that there is at least one among the small re tangles whose distan es from the four sides of R are either all odd or all even. (Singapore)