#include <stdio.h>

int main() {
    int a, b;
    while (scanf("%d %d", &a, &b) != EOF) 
    {
        int n = 0;
        n = a ^b;
        int count = 0;
        while(n)
        {
           if(n%2 == 1)//算二进制最右边的1
                count++;
            n >>= 1;//或者 n = n / 2;
        }
        printf("%d",count);
    }
    return 0;
}