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 Java (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.math.BigInteger;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);

		// 整数の数
		int N = scan.nextInt();

		BigInteger ans = BigInteger.ONE;

		List<Long>  list = new ArrayList();

		for(int i = 0; i < N; i++) {
			list.add(scan.nextLong());
		}

		// ansに掛け算の結果
		for(int i = 0; i < list.size(); i++) {
			ans = ans.multiply(BigInteger.valueOf(list.get(i)));
		}

		//9223372036854775807

		//18446744073709551616
		System.out.println(ans.toString().length() );
		if(ans.toString().length() > 19 ) {
			System.out.println(-1);
		}else {
			System.out.println(ans.longValue());
		}

	}

}