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)


function Main(input) {
    // 1行目がinput[0], 2行目がinput[1], …に入る
    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
 
  let a = parseInt( input[0].split(" ",10)[0] );//分割代入
  let b = parseInt( input[0].split(" ",10)[1] );//分割代入
  let c = parseInt( input[0].split(" ",10)[2] );
  let d = parseInt( input[0].split(" ",10)[3] );//分割代入
  
    let ary = [];
    ary.push(a*c);
    ary.push(a*d);
    ary.push(b*c);
    ary.push(b*d);
    let res = Math.max(...ary);

    //出力
    console.log(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"));