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 Kotlin (1.0.0) (judge verdict: Wrong Answer)

import java.math.BigDecimal

fun main(args: Array<String>) {
    val l = readLine()!!.toInt() * 10
    var a = 0L
    for (x in 1..l-2) {
        for (y in 1 until x) {
            val z = l-x-y
            val a2 = x.toLong() * y.toLong() * z.toLong()
            if (a < a2) {
                a = a2
            }
        }
    }
    println(BigDecimal.valueOf(a/1000.00).setScale(6).toPlainString())
}