#include <bits/stdc++.h>
using namespace std;
int main() {
  string s1, s2;
  int count1 = 0, count2 = 0;
  while (cin >> s1 >> s2) {
    for (; s1[count2] != '\0';) {
      if (s1[count1] != s2[count2])
        cout << 1;
      else
        cout << 0;
      count1++;
      count2++;
    }
    count1 = 0;
    count2 = 0;
    cout << endl;
  }
  return 0;
}
