import java.util.*;

public class Main {
    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        
        long mx = (long)Math.pow(10, 18);
        
        long ans = 1;
        for(int i = 0; i < n; i++) {
            long next = sc.nextLong();
            if(next == 0) {
                ans = 0;
                break;
            }
            if(ans == -1) continue;
            if(ans > mx/next || ans*next > mx) {
                ans = -1;
            } else {
                ans *= next;
            }
        }
        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