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: Accepted)

package main

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

var limit uint64 = 1

func init() {
	for i := 0; i < 18; i++ {
		limit *= 10
	}
}

func main() {
	N := readlineint()[0]
	In := readlineint()

	for _, v := range In {
		if v == 0 {
			fmt.Println("0")
			return
		}
	}

	var previous_result uint64 = 1
	var result uint64 = 1
	for i := 0; i < N; i++ {
		previous_result = result
		result *= uint64(In[i])

		if result > limit || previous_result > result {
			fmt.Println("-1")
			return
		}
	}
	fmt.Println(result)
}

/////////////////////////////////////////

func fln(format string, elements ...interface{}) {
	fmt.Printf(format+"\n", elements...)
}

var bufreader = bufio.NewReaderSize(os.Stdin, 1e6)

func readline() string {
	a, _, _ := bufreader.ReadLine()
	return string(a)
}

func readlineint() (result []int) {
	in := strings.Split(readline(), " ")
	result = make([]int, 0, 2)
	for _, v := range in {
		t, _ := strconv.Atoi(v)
		result = append(result, t)
	}
	return
}