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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.*;
import java.io.BufferedInputStream;

public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner (new BufferedInputStream(System.in));
    int n = sc.nextInt();
    int res = 0;
    for(int i = 1; i <= n; ++i) {
      for(int j = i; j <= n - i; ++j) {
        int k = n - i - j;
        res = Math.max(res, i * k * j);
      }
    }
    System.out.println(Math.pow((double)n / 3, 3) );
  }
}