import java.util.Arrays;
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);

        int a = scan.nextInt();
        long result = 1;
        long[] c = new long[a];
        long b = (long) Math.pow(10,18);

        for (int i = 0; i < a; i++) {
            c[i] = scan.nextLong();

        }

        Arrays.sort(c);
        if (c[0] == 0) {
            System.out.println(0);
            scan.close();
            return;
        }

            for (int j = 0; j < a; j++) {
                if (result > b/c[j]) {
                    System.out.println(-1);
                    scan.close();
                    return;
                }
                result *= c[j];
            }

            System.out.println(result);
            scan.close();

    }

}
/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