import java.util.*;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    long ans = 1;
    int n = sc.nextInt();

    for (int i = 0; i < n; i++) {
      long next = sc.nextLong();

      if (ans != -1) {
        if (1000000000000000000L / next < ans) {
          ans = -1;
        } else {
          ans *= next;
        }
      } else {
        if (next == 0) {
          ans = 0;
          break;
        }
      }
    }

    System.out.println(ans);
  }
}

/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz