#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define fi first
#define se second
int main(){
    string a, b;
    cin >> a >> b;
    int as = a.size(), bs = b.size();

    ll ans = 0;
    for(int i = 0; i < max(as, bs); i++){
        
        if(i < min(as, bs)) ans += (((a[as - 1 - i] - '0' + b[bs - 1 - i] - '0') % 2) << i);
        else if(as < bs){
            ans += ((b[bs - 1 - i] - '0') << i);
        }
        else{
            ans += ((a[as - 1 - i] - '0') << i);
        }
    }
    cout << ans << endl;
    return 0;
}