The Hamming distance between two integers is the number of positions at which the corresponding bits are different. Given two integers x and y, calculate the Hamming distance.

class Solution(object):
    def hammingDistance(self, x, y):
        xor = x ^ y
        count = 0
        for _ in xrange(32):
            if xor & 1 == 1:
                count += 1
            xor >>= 1
        return count