#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1000000007;
const int MAX = 2003;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  string inp1, inp2;
  getline(cin, inp1);
  getline(cin, inp2);
  for (long long i = 0; inp1[i]; ++i) {
    if (inp1[i] != inp2[i])
      cout << "1";
    else
      cout << "0";
  }
  cout << '\n';
  return 0;
}
