The rest of the board cannot be cut into staircases
Source: MEMO 2018 I2
September 7, 2018
memocombinatoricsinvariantColoring
Problem Statement
The two figures depicted below consisting of and unit squares, respectively, are called staircases.
Consider a board consisting of cells, each being a unit square. Two arbitrary
cells were removed from the same row of the board. Prove that the rest of the board cannot be cut (along the cell borders) into staircases (possibly rotated).