#include <bits/stdc++.h>
#pragma comment(linker, "/stack:64000000")
using namespace std;
const double PI = 2 * acos(0.0);
const double eps = 1e-9;
template <class T>
T jog(T a, T b) {
  return a + b;
}
template <class T>
T bog(T a, T b) {
  return a - b;
}
template <class T>
T gon(T a, T b) {
  return a * b;
}
template <class T>
T sq(T x) {
  return x * x;
}
template <class T>
T gcd(T a, T b) {
  return b == 0 ? a : gcd(b, a % b);
}
template <class T>
T lcm(T a, T b) {
  return (a / gcd(a, b)) * b;
}
template <class T>
T power(T a, T p) {
  T res = 1, x = a;
  while (p) {
    if (p & 1) res = res * x;
    x = x * x;
    p >>= 1;
  }
  return res;
}
template <class T>
T cordinatlenth(T a, T b, T c, T d) {
  return sqrt(sq(a - c) + sq(b - d));
}
template <class T>
string toString(T n) {
  ostringstream oss;
  oss << n;
  oss.flush();
  return oss.str();
}
int toInt(string s) {
  int r = 0;
  istringstream sin(s);
  sin >> r;
  return r;
}
long long bigmod(long long a, long long p, long long mod) {
  long long res = 1, x = a;
  while (p) {
    if (p & 1) res = (res * x) % mod;
    x = (x * x) % mod;
    p >>= 1;
  }
  return res;
}
int diraction1[] = {-1, 0, 0, 1, 1, -1, -1, 1};
int diraction2[] = {0, -1, 1, 0, 1, -1, 1, -1};
int horsed1[] = {-2, -2, -1, 1, 2, 2, 1, -1};
int horsed2[] = {1, -1, -2, -2, -1, 1, 2, 2};
double TOTAL_TIME;
void f();
const int INF = 2147483647;
const long long LINF = 9223372036854775807ll;
long long i, j, k, n, m;
int main() {
  TOTAL_TIME = clock();
  f();
  TOTAL_TIME = clock() - TOTAL_TIME;
  return 0;
}
void f() {
  int n, m, k, r, c, x;
  string a, b;
  while (cin >> a) {
    cin >> b;
    n = a.length();
    for (i = 0; i < n; i++) {
      if (a[i] != b[i])
        a[i] = '1';
      else
        a[i] = '0';
    }
    cout << a << endl;
  }
}
