#include <bits/stdc++.h>
using namespace std;
int32_t main() {
  long long int n, res = 1;
  cin >> n;
  vector<string> v(n);
  for (long long int i = 0; i < n; i++) cin >> v[i];
  for (long long int i = 0; i < n; i++)
    if (v[i] == "0") {
      cout << 0 << endl;
      return 0;
    }
  vector<long long int> ans;
  long long int cnt = 0;
  string str;
  for (long long int i = 0; i < n; i += 1) {
    string x = v[i];
    long long int j = x.length() - 1;
    for (; j >= 0; j--) {
      if (x[j] == '0') {
        cnt += 1;
      } else
        break;
    }
    if (x.substr(0, j + 1) == "1") continue;
    str += x.substr(0, j + 1);
  }
  if (str.size() == 0) str += '1';
  for (long long int i = 0; i < cnt; i++) str += '0';
  cout << str << endl;
  return 0;
}
