import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		long ans = 1;
		int check = 0;
		long[] a = new long[n];
		for(int i = 0; i < a.length; ++i){
          a[i] = sc.nextLong();
          if(a[i]==0){
              check = 1;
          }
        }
        int[] b = new int[18];
        for(int j=0; j<18; ++j){
            b[j] = 10;
        }
        long num = 1;
        for(int j=0; j<18; ++j){
            num = num*b[j];
        }
         for(int i=0; i<n; ++i){
           if(a[i]<=num/ans){
            ans = ans*a[i];
           }else{
             ans=0;
          	break;
           }
         }
         if(check == 0){
             if(ans == 0){
             System.out.println("-1");
            }else{
              System.out.println(ans);
            }
         }else{
             System.out.println("0");
         }
	}
}

/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