import java.util.*;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        long currentA = 1;
        long[] vals = new long[N];
        for (int i = 0; i < N; i++) {
            vals[i] = sc.nextLong();
        }
        Arrays.sort(vals);
        if (vals[0] == 0) {
            System.out.println(0);
        } else {
            for (int i = 0; i < N; i++) {
                if (currentA > 1000000000000000000L / vals[i]) {
                    currentA = -1;
                    break;
                }
                currentA *= vals[i];
            }
            System.out.println(currentA);
        }

    }
}

/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