#include <bits/stdc++.h>
using ll = long long;
using namespace std;
#define rep(i, a, b) for (ll i = a; i < ll(b); ++i)

int main() {
    bitset<30> a, b;
    cin >> a >> b;
    auto c = a ^ b;
    int ans = 0;
    rep(i, 0, 30) {
        if (c[30 - i] == 1) {
            ans *= 2;
        }
    }
    cout << ans << endl;
}