#include <bits/stdc++.h>
using namespace std;

int main()
{
    int A, B;
    cin >> A >> B;
    int ans = 0;
    for (int bit = 0; bit <= 8; bit++)
    {
        int A_bit = (A >> bit) & 1;
        int B_bit = (B >> bit) & 1;
        if (A_bit + B_bit == 1)
        {
            ans |= (1 << bit);
        }
    }
    cout << ans;
}