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 Python (3.8.2) (judge verdict: Accepted)

s = input().split()
x_min = int(s[0])
x_max = int(s[1])

y_min = int(s[2])
y_max = int(s[3])

if(x_max>0 and y_max>0 and x_min>0 and y_min>0):
	print(x_max*y_max)
elif(x_max<0 and y_max < 0 and x_min<0 and y_min < 0):
  	print(x_min * y_min)
elif(x_max < 0 and y_min > 0):
  	print(x_max * y_min)
elif(x_min > 0 and y_max < 0):
  	print(x_min * y_max)
else:
	if(x_min * y_min > x_max * y_max):
		print(x_min * y_min)
	else:
		print(x_max * y_max)