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: Wrong Answer)

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

class Program
{
    static void Main(string[] args)
    {
        var n = long.Parse(Console.ReadLine());

        var a = Console.ReadLine().Split(' ').Select(long.Parse).ToArray();

        long tmp = 1;

        // 桁数を毎回調べる
        for (int i = 0; i < n; i++)
        {
            if(a[i] == 0)
            {
                tmp = -1;
                break;
            }

            if(a[i].ToString().Length > 20)
            {
                tmp = -1;
                break;
            }

            var keta1 = tmp.ToString().Length - 2;
            var keta2 = a[i].ToString().Length - 2;

            if(keta1 + keta2 + 1 > 18)
            {
                tmp = -1;
                break;
            }

            tmp *= a[i];

            if (tmp > 1000000000000000000 || tmp < -1)
            {
                tmp = -1;
                break;
            }
        }

        Console.WriteLine(tmp);
    }
}