#include <bits/stdc++.h>
using namespace std;
int get_min(stack<int> ss) {
  stack<int> tmp = ss;
  int ans = tmp.top();
  while (tmp.size() != 0) {
    if (tmp.top() < ans) {
      ans = tmp.top();
    }
    tmp.pop();
  }
  return ans;
}
void to_small(string& a) {
  for (int i = 0; i < a.size(); ++i) {
    if (a[i] >= 65 && a[i] <= 91) {
      a[i] += 32;
    }
  }
}
int get_lex(string& a, string& b) {
  to_small(a);
  to_small(b);
  if (a == b) {
    return 0;
  }
  int m, n, i;
  m = a.size();
  n = b.size();
  int mn = m < n ? m : n;
  for (i = 0; i < mn; ++i) {
    if (a[i] > b[i]) {
      return 1;
    } else if (a[i] < b[i]) {
      return -1;
    } else {
      continue;
    }
  }
}
const int mx = 5;
void solve_matrix() {
  int matrix[mx][mx];
  for (int i = 0; i < mx; ++i) {
    for (int j = 0; j < mx; ++j) {
      cin >> matrix[i][j];
    }
  }
  bool flg = false;
  int row, col;
  for (int i = 0; i < mx; ++i) {
    for (int j = 0; j < mx; ++j) {
      if (matrix[i][j] == 1) {
        flg = true;
        row = i;
        col = j;
        break;
      }
    }
    if (flg == true) {
      break;
    }
  }
  int a = abs(2 - row);
  int b = abs(2 - col);
  cout << (a + b) << endl;
}
void wrong_substruction() {
  int n, k;
  cin >> n >> k;
  int t = k;
  while (t--) {
    if (n % 10 == 0) {
      n /= 10;
    } else {
      n--;
    }
  }
  cout << n << endl;
}
void solve_george() {
  int n;
  cin >> n;
  int a, b, ans = 0;
  int t = n;
  while (t--) {
    cin >> a >> b;
    if ((b - a) >= 2) {
      ans++;
    }
  }
  cout << ans << endl;
}
inline void lucky_number() {
  string s;
  cin >> s;
  for (int i = 0; i < s.size(); ++i) {
    if (s[i] == '4' || s[i] == '7') {
      continue;
    } else {
      cout << "NO" << endl;
      return;
    }
  }
  cout << "YES" << endl;
}
inline int num_of_digit(long long num) {
  int ans = 0;
  while (num != 0) {
    ans++;
    num /= 10;
  }
  return ans;
}
inline void anton_danik() {
  int n;
  cin >> n;
  string str;
  int t = n;
  char c;
  while (t--) {
    cin >> c;
    str += c;
  }
  int a = 0, d = 0;
  for (int i = 0; i < n; ++i) {
    if (str[i] == 'D') {
      d++;
    } else if (str[i] == 'A') {
      a++;
    }
  }
  if (a > d) {
    cout << "Anton" << endl;
  } else if (a < d) {
    cout << "Danik" << endl;
  } else {
    cout << "Friendship" << endl;
  }
}
bool is_distinct(int n) {
  int a, b, c, d;
  a = n % 10;
  n = n / 10;
  b = n % 10;
  n = n / 10;
  c = n % 10;
  n = n / 10;
  d = n % 10;
  if ((a != b) && (a != c) && (a != d) && (b != c) && (b != d) && (c != d)) {
    return true;
  } else {
    return false;
  }
}
inline void beuty_year() {
  int year;
  cin >> year;
  int y = year;
  if (is_distinct(year)) {
    year++;
  }
  while (!(is_distinct(year))) {
    year++;
  }
  cout << year;
}
inline void fence() {
  long long n, h;
  cin >> n >> h;
  long long x;
  long long ans = 0;
  while (n--) {
    cin >> x;
    if (x > h) {
      ans += 2;
    } else {
      ans += 1;
    }
  }
  cout << ans << endl;
}
inline void hard() {
  int n, o;
  cin >> n;
  while (n--) {
    cin >> o;
    if (o == 1) {
      cout << "HARD\n";
      return;
    } else {
      continue;
    }
  }
  cout << "EASY\n";
}
inline void hulk() {
  int n;
  cin >> n;
  for (int i = 1; i <= n; ++i) {
    if (i % 2 != 0) {
      cout << "I hate";
      if (i != n) {
        cout << " that ";
      } else {
        cout << " it";
      }
    } else {
      cout << "I love";
      if (i != n) {
        cout << " that ";
      } else {
        cout << " it";
      }
    }
  }
}
inline void magnet() {
  int n;
  cin >> n;
  string s;
  string a[n];
  for (int i = 0; i < n; ++i) {
    cin >> a[i];
  }
  int ans = 1;
  for (int i = 0; i < n - 1; ++i) {
    if (a[i] != a[i + 1]) {
      ans++;
    }
  }
  cout << ans << endl;
}
inline void numbers() {
  int num[101];
  for (int i = 0; num[i] != (int)('\n'); ++i) {
    cin >> num[i];
  }
  for (auto& x : num) {
    cout << x;
  }
}
inline void bank() {
  int t, n;
  cin >> t;
  while (t--) {
    cin >> n;
    vector<string> v;
    while (n--) {
      string s;
      getline(cin, s);
      v.push_back(s);
    }
    sort(v.begin(), v.end());
    for (auto& x : v) {
      cout << x << endl;
    }
  }
}
inline void maths() {
  string a, b;
  cin >> a >> b;
  for (int i = 0; i < a.size(); ++i) {
    if (a[i] == b[i]) {
      cout << '0';
    } else if (a[i] != b[i]) {
      cout << '1';
    }
  }
}
int main() {
  maths();
  return 0;
}
