import java.util.*;

public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);

    int n = sc.nextInt();
    long[] a = new long[n];
    long ans = 1;
    long max = (long)Math.pow(10, 18);

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

    for(int i = 0; i < n; i++){
      if(a[i] <= max / ans){
        ans *= a[i];
      } else {
        ans = -1;
        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