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 Java (OpenJDK 11.0.6) (judge verdict: Wrong Answer)

//package com.company;
import java.util.*;
import java.io.*;
import java.lang.*;


public class Main {

    public static void main(String[] args) {
	// write your code here

      //  System.out.println("Hello World");
        // System.out.println("This is my first package ");
        Scanner s=new Scanner(System.in);
        long a=s.nextLong();
        long b=s.nextLong();
        long c=s.nextLong();
        long d=s.nextLong();

        long res=0,max=0;
      /*  res=Integer.MIN_VALUE;
        max=Integer.MIN_VALUE;
        for(long i=a;i<=b;i++)
        {
            for(long j=c;j<=d;j++)
            {
                max=i*j;
                res=Math.max(max,res);
            }
        }*/
      long p=a*c;
      long q=b*d;
      res=Math.max(p,q);
        System.out.println(res);



    }
}