#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, f0 = 0, total = 0;
  scanf("%d", &n);
  string save = "1";
  while (n--) {
    int tmp = 0, ff = 0;
    string s;
    cin >> s;
    if (s[0] == '0') {
      cout << "0";
      return 0;
    }
    if (s[0] != '1') {
      ff = 1;
      save = s;
    }
    int fi = 0;
    if (ff == 0 && f0 == 0) {
      int sz = s.size(), ctr2 = 0;
      for (int i = 0; i < sz; i++) {
        if (s[i] == '1') ctr2++;
        if (ctr2 > 1 || (s[i] != '0' && s[i] != '1')) {
          fi = 1;
          save = s;
          break;
        }
        if (s[i] == '0') tmp++;
      }
    }
    if (fi == 0) {
      total += tmp;
    }
  }
  cout << save;
  for (int i = 0; i < total; i++) cout << "0";
  return 0;
}
