I need help with a problem:

Chess board 2018x 2018 was covered with one square plate 2x2 and [tex]\frac{2018^{2} - 4}{5}[/tex] rectangole plates 1x5 in the way that every field is covered by exactly one plate (you can rotate plates) You have to prove that plate 2x2 DO NOT COVER any of the fields on the edge of board.

Please help me, i dont have concept how to start

Thanks