+1 for changing output type to Integer.

I've cheated here writing actual hamming signature as Int -> Integer and it passed all tests anyway so there are no overflows in the testing environment. But the Haskell translation of the kata should be definitely changed because Haskell standard guarantees only that Int values are at least in [-2^29 ... 2^29-1] and hamming 5000 is greater that 2^45.