#include <bits/stdc++.h>
using namespace std;
int sum(int n) {
  if (n == 1) return 1;
  return n + sum(n - 1);
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.setf(ios::fixed);
  cout.precision(12);
  string s1, s2;
  cin >> s1 >> s2;
  for (int i = 0; i < s1.size(); ++i) {
    s1[i] == s2[i] ? cout << 0 : cout << 1;
  }
  cout << endl;
  return 0;
}
