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.Numerics;

namespace AtCoderTest
{
    class Program
    {
        static void Main(string[] args)
        {
            int a = int.Parse(Console.ReadLine());
            // スペース区切りの整数の入力
            string[] input = Console.ReadLine().Split(' ');
            if (input.Contains("0"))
            {
                Console.WriteLine(0);
                return;
            }
            BigInteger result = 0;
            BigInteger current = BigInteger.Parse(input[0]); ;
            BigInteger max = 1000000000000000000;
            // スペース区切りの整数の入力
            for (int i = 1; i < a; i++){
                BigInteger b = BigInteger.Parse(input[i]);
                if (b == 0)
                {
                    result = 0;
                    break;
                }
                if (b > max)
                {
                    result = -1;
                    break;
                }

                result = current * b;
                if (result > max)
                {
                    result = -1;
                    break;
                }
                else
                {
                    current = result;
                }
            }
            //出力
            Console.WriteLine(result);
        }
/*
 static void _Main(string[] args)
        {
            int a = int.Parse(Console.ReadLine());
            // スペース区切りの整数の入力
            string[] input = Console.ReadLine().Split(' ');
            int b = int.Parse(input[0]);
            int c = int.Parse(input[1]);
            // 文字列の入力
            string s = Console.ReadLine();
            //出力
            Console.WriteLine((a + b + c) + " " + s);
        }
*/
    }
}