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++ (GCC 9.2.1) (judge verdict: Wrong Answer)

#include <iostream>

using namespace std;

size_t digits(unsigned long long a) {
    unsigned long long n = a;
    size_t count = 0;
    while (n > 0) {
        n /= 10;
        ++count;
    }
    return count;
}

int main() {
    unsigned long long n;
    cin >> n;
    unsigned long long result = 1;
    unsigned long long digit = 0;
    for (unsigned long long i = 0; i < n; ++i) {
        unsigned long long a;
        cin >> a;
        digit += (digits(a) - 1);
        result *= a;
    }
    if (result > 1000000000000000000 || (digit > 18 && result != 0)) {
        cout << -1 << endl;
    }
    else {
        cout << result << endl;
    }
    return EXIT_SUCCESS;
}