text: #include<bits/stdc++.h>
  using namespace std;
  
  int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(NULL);
    string s;
    int zeros = 0, ones = 0, n;
    cin >> n >> s;
    for (int i = 0; i < n; ++i)
      if (s[i] == '0')
        zeros++;
    ones = n - zeros;
    if (ones)
      cout << 1;
    for (int i = 0; i < zeros; ++i)
      cout << 0;
    return 0;
  }
  