Problem:
Score : 200 points

Problem Statement

Given N integers A_1, ..., A_N, compute A_1 \times ... \times A_N.

However, if the result exceeds 10^{18}, print -1 instead.

Constraints

2 \leq N \leq 10^5

0 \leq A_i \leq 10^{18}

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N
A_1 ... A_N

Output

Print the value A_1 \times ... \times A_N as an integer, or -1 if the value exceeds 10^{18}.

Sample Input 1

2
1000000000 1000000000

Sample Output 1

1000000000000000000

We have 1000000000 \times 1000000000 = 1000000000000000000.

Sample Input 2

3
101 9901 999999000001

Sample Output 2

-1

We have 101 \times 9901 \times 999999000001 = 1000000000000000001, which exceeds 10^{18}, so we should print -1 instead.

Sample Input 3

31
4 1 5 9 2 6 5 3 5 8 9 7 9 3 2 3 8 4 6 2 6 4 3 3 8 3 2 7 9 5 0

Sample Output 3

0

Solution in C# (.NET Core 3.1.201) (judge verdict: Accepted)

using System;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static void Main(string[] arg){
        int N = int.Parse(Console.ReadLine());     
        string[] tmp = Console.ReadLine().Split(' ');
        ulong[] num = new ulong[N];

        for(int i=0;i<N;i++){
            num[i] = ulong.Parse(tmp[i]);
            if(num[i]==0){
                Console.WriteLine("0");
                return;
            }
        }
        
        ulong ret = 1;
        
        try{
            checked{
                for(int i=0;i<N;i++){
                    ret *= num[i];
                }
            }
        }
        catch(OverflowException ex){
            Console.WriteLine("-1");
            return;
        }

        if(ret>(ulong)Math.Pow(10,18)){
            Console.WriteLine("-1");
            return;
        }else{
            Console.WriteLine(ret);
        }

        return;
    }
}