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"
    "math/big"
    "os"
    "strconv"
    "strings"
)

var sc = bufio.NewReaderSize(os.Stdin, 1024*1024*10)

func main() {
    N := getStdinInt()
    A := getStdinIntArr64()
    Abig := make([]*big.Int, N)
    for i := 0; i < N; i++ {
        Abig[i] = big.NewInt(A[i])
    }

    for i := range A {
        if A[i] == 0 {
            fmt.Println(0)
            return
        }
        if A[i] > 1000000000000000000 {
            fmt.Println(-1)
            return
        }
    }

    ans := big.NewInt(1)
    cmp := big.NewInt(1000000000000000000)

    for i := range Abig {
        ans = ans.Mul(ans, Abig[i])
        if ans.Cmp(cmp) == 1 {
            fmt.Println(-1)
            return
        }
    }

    fmt.Println(ans)
}


func getStdin() string {
    return readLine()
}
func getStdinInt() int {
    str := getStdin()
    res, _ := strconv.Atoi(str)
    return res
}
func getStdinintArr() []int {
    str := getStdin()
    list := strings.Split(str, " ")
    res := make([]int, len(list))
    for idx, v := range list {
        res[idx], _ = strconv.Atoi(v)
    }
    return res
}
func getStdinIntArr64() []int64 {
    str := getStdin()
    list := strings.Split(str, " ")
    res := make([]int64, len(list))
    for idx, v := range list {
        res[idx], _ = strconv.ParseInt(v, 10, 64)
    }
    return res
}
func readLine() string {
    buf := make([]byte, 0, 0)
    for {
        l, p, e := sc.ReadLine()
        if e != nil {
            panic(e)
        }
        buf = append(buf, l...)
        if !p {
            break
        }
    }
    return string(buf)
}