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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace abc159_c
{
    class Program
    {
        static void Main(string[] args)
        {
            var L = CIn.ReadInt();
            var i = (double)L / 3;
            var ans = Math.Pow(i, 3);
            Console.WriteLine(ans);
        }
    }
}
class CIn
{
    private static readonly Queue<string> fieldBuffer = new Queue<string>();

    public static string Read()
    {
        if (fieldBuffer.Count == 0)
        {
            foreach (var field in Console.ReadLine().Split())
            {
                fieldBuffer.Enqueue(field);
            }
        }

        return fieldBuffer.Dequeue();
    }

    public static int ReadInt() => int.Parse(Read());
    public static long ReadLong() => long.Parse(Read());
    public static double ReadDouble() => double.Parse(Read());

    public static string[] ReadStringArray(long n)
    {
        var array = new string[n];

        for (var i = 0; i < n; i++)
        {
            array[i] = Read();
        }

        return array;
    }

    public static int[] ReadIntArray(long n)
    {
        var array = new int[n];

        for (var i = 0; i < n; i++)
        {
            array[i] = ReadInt();
        }

        return array;
    }

    public static long[] ReadLongArray(long n)
    {
        var array = new long[n];

        for (var i = 0; i < n; i++)
        {
            array[i] = ReadLong();
        }

        return array;
    }
    public static double[] ReadDoubleArray(long n)
    {
        var array = new double[n];

        for (var i = 0; i < n; i++)
        {
            array[i] = ReadDouble();
        }

        return array;
    }
}