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;

public class Program
{

    static void Main()
    {
        var maxValue = Enumerable.Repeat(10L, 18).Aggregate((a, b) => a * b);
        Console.ReadLine();
        var product = Console.ReadLine().Split(" ")
                                        .Select(s => long.Parse(s))
                                        .Aggregate((prev, curr) => {
                                            if(prev == 0 || curr == 0)
                                            {
                                                return 0;
                                            }

                                            if(prev == -1)
                                            {
                                                return -1;
                                            }

                                            try
                                            {
                                                var product = checked (prev * curr);
                                                if (product > maxValue)
                                                {
                                                    return -1;
                                                }
                                                return prev * curr;
                                            } 
                                            catch (OverflowException)
                                            {
                                                return -1;
                                            }
                                        });
         Console.Write(product);
    }
}