import java.util.*;
import java.math.*;
import java.lang.*;

public class Main {

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

    for (int i = 0; i < n; i++) {
      a[i] = sc.nextLong();
      if (a[i] == 0) {
        System.out.println(0);
        return;
      }
    }

    Arrays.sort(a);

    long ans = 1;

    for (int i = 0; i < n; i++) {
      if (ans > 1000000000000000000L/a[i]) {
        System.out.println(-1);
        return;
      }
      ans *= a[i];
    }

    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