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: Wrong Answer)

package main

import (
	"bufio"
	"fmt"
	"math"
	"os"
	"strconv"
)

func main() {
	var t string
	var s = bufio.NewScanner(os.Stdin)
	s.Split(bufio.ScanWords)

	if s.Scan() {
		t = s.Text()
	}

	N, err := strconv.Atoi(t)
	if err != nil {
		return
	}

	// var answer int64
	// answer = 1

	// for i := 0; i < N; i++ {

	// 	if s.Scan() {
	// 		t = s.Text()
	// 	}

	// 	v, err := strconv.ParseInt(t, 10, 64)
	// 	if err != nil {
	// 		return
	// 	}
	// 	if v == 0 {
	// 		fmt.Println(0)
	// 		return
	// 	} else {
	// 		answer = answer * int64(v)
	// 	}
	// }

	// if answer > int64(math.Pow10(18)) {
	// 	fmt.Println(-1)
	// 	return
	// }
	// fmt.Println(answer)

	var arr []int64
	for i := 0; i < N; i++ {
		if s.Scan() {
			t = s.Text()
		}

		v, err := strconv.ParseInt(t, 10, 64)
		if err != nil {
			fmt.Println(err)
			return
		}
		if v == 0 {
			fmt.Println(0)
			return
		} else {
			arr = append(arr, v)
		}
	}

	var answer int64
	answer = 1
	for _, v := range arr {
		// if v > int64(math.Pow10(18)) {
		// 	fmt.Println(-1)
		// 	return
		// }
		answer = int64(answer * v)
		if answer < 0 {
			fmt.Println(-1)
			return
		}
	}

	if answer > int64(math.Pow10(18)) {
		fmt.Println(-1)
		return
	}
	if answer < 0 {
		fmt.Println(-1)
		return
	}
	fmt.Println(answer)

}