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.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner scanner = new Scanner(System.in);
		int l = scanner.nextInt();
//		double result = 0;
//		for(int i = 1; i <= l-2; i++){
//			for(int j = l-i-1; j >= 1; j--){
//				int k = l - i - j;
//				result = Math.max(result, i*j*k);
////				System.out.println(i+","+j+","+k+" : " + result);
//			}
//		}
		double rrr = 0d;
		double a = 0.1d;
		while(a <= l - 0.2d){
			double b = l - a;
			while(b > 0){
				double c = l - a - b;
				rrr = Math.max(rrr, a * b * c);
				b -= 0.1d;
			}
			a += 0.1d;
		}
		float ll = l;

		System.out.println(ll/3*(ll/3)*(ll/3));
	}

}