#include <stdio.h>

int countBits(int);

int hammingDistance(int x, int y) {
    return countBits(x ^ y);
}

int countBits(int v) {
    int c;
    for (c = 0; v; v >>= 1) {
        c += v & 1;
    }
    return c;
}

int main() {
    printf("Expected: 2\n");
    printf("Got: %d\n", hammingDistance(1, 4));
    return 0;
}