Question 12
As shown in the diagram below, David has eight shaded pieces (labelled as A, B, …, G, H) that are placed on the $11\times11$ game board. Each piece is to be pushed, in a certain order, into the game board such that every piece must align along the grid lines and no part of any piece remains outside the board or overlapping. After David pushes all eight shaded pieces in this order, which piece will be pushed last?
