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

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

    long limit = (long) Math.pow(10,18);
    long sum = 1;
    long [] c = new long[a];
    for (int i=0;i<a;i++){
      long b = scan.nextLong();
      if (b==0){
        System.out.println(0);
        return;
      }
      c[i] = b;
    }

    for (int j=0;j<a;j++){
      if (Math.log10(sum)+Math.log10(c[j])>18){
        System.out.println(-1);
        return;
      }
      sum*=c[j];
    }

    if (sum>limit){
      System.out.println(-1);
      return;
    }
    System.out.println(sum);
  }
}

/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