UVA_10469_To_Carry_Or_Not

#include <iostream>
#include <cstdio>
#include <stdio.h>
#include <algorithm>
#include <cstring>
#include <cctype>
#include <sstream>
#include <stdlib.h>
#include <cmath>
using namespace std;
int main() {
    int a,b;
    int result;
    while(scanf("%d %d",&a,&b)!=EOF){
        result= a^b;
        printf("%d\n",result);
    }

    return 0;
}