import java.util.Scanner;
import java.util.Arrays;
public class Main{
        public static void main(String[] args){
                final Scanner cin = new Scanner(System.in);
                int n = cin.nextInt();
                long[] arr=new long[n];
                for(int i=0;i<n;i++){
                        arr[i]=cin.nextLong();
                }   
                Arrays.parallelSort(arr);
                if(arr[0]==0){
                        System.out.print(0);
                        return;
                }   
                long mul=1L;
                for(long a:arr){
                        if(mul*1.0*a>(long)1e18){
                                System.out.print(-1);
                                System.exit(0);
                        }   
                        mul=mul*a;
                }   
                System.out.print(mul>(long)1e18?-1:mul);
        }   
}
/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