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 1.8.0) (judge verdict: Wrong Answer)

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		
		Scanner in = new Scanner(System.in);
	
		
		
		
			long a = in.nextLong(),b=in.nextLong(),c=in.nextLong(),d=in.nextLong();
			if( ( a* b>=0 && a * c >=0 && a * d>=0)) {
				long max1 = Math.max( a * b, a * c);
				long ans =  Math.max(max1, a * d);
				System.out.println(ans);
			}
			else {
				long min1 = Math.max( a * b, a * c);
				long ans1 =  Math.min(min1, a * d);
				System.out.println(ans1);
			}
		
		
		
		
		
	}

}