import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
      	int n = sc.nextInt();
      	long N = (long)Math.pow(10,18);
      	long[] num = new long[n];
      	long ans = 1;
      	boolean overF = false;
      	boolean zeroF = false;
		for(int i=0;i<n;i++){
			num[i] = sc.nextLong();
          	if( num[i] == 0 ){
              zeroF = true;
              break;
            }
        }
      if( !zeroF ){
     	for(int i=0;i<n;i++){
          	if( ans * num[i] > N || ( ( ans>100000000)&&(num[i]>1000000000) )  ){
              overF = true;
              break;
            }
          ans *= num[i];
        }
      }
      if( zeroF ){
        ans = 0;
      }else if( overF ){
        ans = -1;
      }else{
      
      }         
       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