import java.math.BigInteger;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n=sc.nextInt();
        BigInteger ans = new BigInteger("1");
        boolean b = true;
        String[] s = new String[n];
        for (int i=0;i<n&&b;i++){
            s[i]=sc.next();
            if (s[i].equals("0")){
                b=false;
                ans=new BigInteger("0");
            }
        }
        for (int i=0;i<n&&b;i++){
            ans=ans.multiply(new BigInteger(s[i]));
            if (ans.toString().length()>18&& !ans.toString().equals("1000000000000000000")){
                b=false;
                ans = new BigInteger("-1");
            }
        }
        System.out.println(ans.toString());
    }
}

/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