Problem:
Score : 300 points

Problem Statement

Given is a positive integer L.
Find the maximum possible volume of a rectangular cuboid whose sum of the dimensions (not necessarily integers) is L.

Constraints

1 ≤ L ≤ 1000

L is an integer.

Input

Input is given from Standard Input in the following format:

L

Output

Print the maximum possible volume of a rectangular cuboid whose sum of the dimensions (not necessarily integers) is L.
Your output is considered correct if its absolute or relative error from our answer is at most 10^{-6}.

Sample Input 1

3

Sample Output 1

1.000000000000

For example, a rectangular cuboid whose dimensions are 0.8, 1, and 1.2 has a volume of 0.96.

On the other hand, if the dimensions are 1, 1, and 1, the volume of the rectangular cuboid is 1, which is greater.

Sample Input 2

999

Sample Output 2

36926037.000000000000

Solution in Python (3.4.3) (judge verdict: Wrong Answer)

# Python3 code to Maximize volume of 
# cuboid with given sum of sides 

# Return the maximum volume. 
def maxvolume(s):
    # finding length
    length = int(s / 3)

    s -= length

    # finding breadth
    breadth = s / 2

    # finding height
    height = s - breadth

    return [length , breadth , height]


# Driven Program
s =int(input())
t=maxvolume(s)
if sum(t)==s:
    print(format((t[0]*t[1]*t[2]), '.10f'))
    #print(t[0]*t[1]*t[2])