#include <bits/stdc++.h>
int main() {
  int i, j, n, a, b, f = 0, u, yaz = 0, t;
  char cvp[100005] = "1";
  scanf("%d", &n);
  for (i = 0; i < n; i++) {
    char arr[100005];
    scanf("%s", arr);
    u = strlen(arr);
    int k = 0;
    f = 0;
    for (j = 0; j < u; j++) {
      if (arr[j] == '0') k++;
      if (arr[j] > '1') f = 1;
      if (arr[0] == '0') {
        printf("0");
        return 0;
      }
    }
    if (f || (u - k) > 1) {
      strcpy(cvp, arr);
    } else
      yaz += k;
  }
  printf("%s", cvp);
  for (i = 1; i <= yaz; i++) printf("0");
  return 0;
}
