#include <bits/stdc++.h>
using namespace std;
const long long int N = 1e6 + 5;
int n, a[N], c, s;
string m, l;
int main() {
  cin >> n;
  for (int i = 0; i < n; ++i) {
    cin >> m;
    if (m[0] == '0') return printf("0"), 0;
    if (m[0] == '1' && m.length() == 1) continue;
    long long int c1 = 0;
    for (int i = 1; i < m.length(); ++i)
      if (m[i] == '0') c1++;
    if (m[0] == '1' && c1 == m.length() - 1) {
      s += m.length() - 1;
    } else {
      c++;
      l = m;
    }
  }
  if (!c) l = '1';
  cout << l;
  for (int i = 0; i < s; ++i) cout << '0';
  return 0;
}
