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 Java7 (OpenJDK 1.7.0) (judge verdict: Accepted)

    import java.io.*;
	import java.util.*;
    class Main
    {
      public static void main(String args[])throws IOException
      {
        double l,x,a;
        BufferedReader input=new BufferedReader(new InputStreamReader(System.in));
        Scanner sc =new Scanner(System.in);
        l=Double.parseDouble(input.readLine());
        x=l/3;
        a=x*x*x;
        System.out.println(a);
      }
    }