Problem:
Score : 200 points

Problem Statement

Given are integers a,b,c and d.
If x and y are integers and a \leq x \leq b and c\leq y \leq d hold, what is the maximum possible value of x \times y?

Constraints

-10^9 \leq a \leq b \leq 10^9

-10^9 \leq c \leq d \leq 10^9

All values in input are integers.

Input

Input is given from Standard Input in the following format:

a b c d

Output

Print the answer.

Sample Input 1

1 2 1 1

Sample Output 1

2

If x = 1 and y = 1 then x \times y = 1.
If x = 2 and y = 1 then x \times y = 2.
Therefore, the answer is 2.

Sample Input 2

3 5 -4 -2

Sample Output 2

-6

The answer can be negative.

Sample Input 3

-1000000000 0 -1000000000 0

Sample Output 3

1000000000000000000

Solution in JavaScript (Node.js 12.16.1) (judge verdict: Wrong Answer)

"use strict";
function Main(input) {
    input = input.split("\n");
 
    //文字列から10進数に変換するときはparseIntを使います
    const arr = input[0].split(" ",4);
    let a = arr[0];
    let b = arr[1];
    let c = arr[2];
    let d = arr[3];
     a = parseInt(a,10);
     b = parseInt(b,10);
     c = parseInt(c,10);
     d = parseInt(d,10);

    let ary = [];
    ary.push(a*c);
    ary.push(a*d);
    ary.push(b*c);
    ary.push(b*d);
    let res = Math.max.apply(null, ary);
    //出力
    console.log( Number(res) );
  
}
//*この行以降は編集しないでください（標準入出力から一度に読み込み、Mainを呼び出します）
Main(require("fs").readFileSync("/dev/stdin", "utf8"));