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 Go (1.6) (judge verdict: Accepted)

package main

import(
	"fmt"
	"os"
	"bufio"
)

func main(){
	in := bufio.NewReader(os.Stdin)
	out := bufio.NewWriter(os.Stdout)

	defer out.Flush()

	var L, output float64

	fmt.Fscanf(in, "%f\n", &L)

	output = (L / 3) *(L / 3) *(L / 3)

	fmt.Fprintf(out, "%.10f\n", output)




}