count sz@(m, n) = countDiamonds sz + m * n * (m + 1) * (n + 1) `div` 4
count sz@(m, n) = countDiamonds sz + m * n * (m + 1) * (n + 1) `div` 4
count sz@(m, n) = countDiamonds sz + m * n * (m + 1) * (n + 1) `div` 4