#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int i, n, flag = 0, tot = 0, len, count;
  char s[100002], s1[100002];
  scanf("%d", &n);
  while (n--) {
    scanf("%s", s);
    len = strlen(s);
    if (len == 1 && s[0] == '0') {
      printf("0\n");
      return 0;
    } else if (!flag) {
      count = 0;
      for (i = 0; i < len; i++) {
        if (s[i] == '1') {
          if (count == 0)
            count++;
          else
            break;
        } else if (s[i] != '0')
          break;
      }
      if (i == len)
        tot += len - 1;
      else {
        for (i = 0; i < len; i++) s1[i] = s[i];
        s1[i] = '\0';
        flag = 1;
      }
    } else
      tot += len - 1;
  }
  if (flag == 1)
    printf("%s", s1);
  else
    printf("1");
  for (i = 0; i < tot; i++) printf("0");
  return 0;
}
