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 <bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;

template <class T>
static inline bool IsOverflow(T a, T b)
{
    return a && b > std::numeric_limits<T>::max() / a;
}

int main()
{
    int n;
    cin >> n;

    constexpr ull border = (ull)10 * 10 * 10 * 10 * 10 * 10 * 10 * 10 * 10 * 10 * 10 * 10 * 10 * 10 * 10 * 10 * 10 * 10;

    bool over = false;
    ull result = 1;
    for (int i = 0; i < n; ++i)
    {
        ull a;
        cin >> a;

        ull next = result * a;
        if (next > border || IsOverflow(result, a))
        {
            over = true;
        }
        result = next;
    }

    if (result == 0)
        over = false;

    if (over)
        cout << -1 << endl;
    else
        cout << result << endl;

    return 0;
}