The answer is 18. Where did yall go to skool? 
eight 1x1 squares, five 2x2 squares, four 3x3 squares, and one 4x4 square.
8+5+4+1=18

eight 1x1 squares, five 2x2 squares, four 3x3 squares, and one 4x4 square.
8+5+4+1=18



