import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		long ans = 1;
		long max = 1000000000000000000l;
		// System.out.println(max);
		List<Long> arr = new ArrayList<>();
		for (int i = 0; i < n; i++) {
			arr.add(sc.nextLong());
		}
		Collections.sort(arr);
		for (int i = 0; i < n; i++) {
			long a = arr.get(i);
			if (a == 0) {
				ans = 0;
				break;
			}
			if (a > max) {
				ans = -1;
				break;
			}
			if (ans > max / a) {
				ans = -1;
				break;
			}
			ans *= arr.get(i);
		}
		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