#include <bits/stdc++.h>
#pragma GCC target("avx2")
#pragma GCC target("popcnt")
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("Ofast")
using namespace std;
string s, t;
int main() {
  cin.tie(0);
  ios_base::sync_with_stdio(0);
  cin >> s >> t;
  for (int i = 0; i < s.size(); ++i) cout << (s[i] != t[i]);
  return 0;
}
