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 Go (1.14.1) (judge verdict: Time Limit Exceeded)

package main

import (
	"bufio"
	"fmt"
	"math/big"
	"os"
	"strconv"
	"strings"
)

func main() {
	var n int
	fmt.Scanf("%d", &n)
	lines, _ := scanLongIntSlices(1, 10000000)
	nums := lines[0]

	prod := big.NewInt(1)
	for _, n := range nums {
		prod.Mul(prod, big.NewInt(int64(n)))
	}
	if prod.Cmp(big.NewInt(1000000000000000000)) > 0 {
		fmt.Println("-1")
	} else {
		fmt.Printf("%s\n", prod.String())
	}
}

func scanLongIntSlices(lines int, maxBufSize int) ([][]int, error) {

	res := [][]int{}

	sc := bufio.NewScanner(os.Stdin)
	buf := make([]byte, bufio.MaxScanTokenSize)
	sc.Buffer(buf, maxBufSize)

	for sc.Scan() {
		line := sc.Text()
		strs := strings.Split(line, " ")
		ints := make([]int, len(strs))
		for i, c := range strs {
			n, err := strconv.Atoi(c)
			if err != nil {
				return nil, err
			}
			ints[i] = n
		}
		res = append(res, ints)
	}

	if err := sc.Err(); err != nil {
		return nil, err
	}

	return res, nil
}