combinatorics
Source: Switzerland Final Round 2021 P7
February 24, 2021
combinatorics
Problem Statement
Let be positive integers. Frieder is given posters of Linus with different integer dimensions of with and . He must put them all up one by one on his bedroom wall without rotating them. Every time he puts up a poster, he can either put it on an empty spot on the wall or on a spot where it entirely covers a single visible poster and does not overlap any other visible poster. Determine the minimal area of the wall that will be covered by posters.