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: Wrong Answer)

//パターン1：OK(小数点以下切り捨て)
import java.math.BigDecimal;
import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int len = sc.nextInt();

		BigDecimal wSide = new BigDecimal((double)len/3);
		BigDecimal tSide = new BigDecimal((double)len/3);
		BigDecimal hSide = new BigDecimal((double)len/3);

		System.out.println(wSide);
		System.out.println(tSide);
		System.out.println(hSide);

		BigDecimal result = wSide.multiply(tSide).multiply(hSide);

		System.out.print(result);
		sc.close();
	}
}


//パターン2：OK(小数点以下6桁以降に桁落ちアリ)
//package ojt.AtCoder;
//import java.util.Scanner;
//public class TestC_159 {
//	public static void main(String[] args) {
//		Scanner sc = new Scanner(System.in);
//		int len = sc.nextInt();
//
//		double wSide = (double)len/3;
//		double tSide = (double)len/3;
//		double hSide = (double)len/3;
//
//		System.out.println(wSide);
//		System.out.println(tSide);
//		System.out.println(hSide);
//
//		double result = wSide*tSide*hSide;
//
//		System.out.print(result);
//		sc.close();
//	}
//}


//パターン3：OK(小数点以下6桁以降に桁落ちアリ)
//package ojt.AtCoder;
//import java.util.Scanner;
//public class TestC_159 {
//	public static void main(String[] args) {
//		Scanner sc = new Scanner(System.in);
//		double len = sc.nextDouble();
//
//		System.out.println(Math.pow(len/3 , 3));
//
//		sc.close();
//	}
//}