    import java.io.*;
	import java.util.*;
    class Main
    {
      public static void main(String args[])throws IOException
      {
        double l,x,a;
        BufferedReader input=new BufferedReader(new InputStreamReader(System.in));
        Scanner sc =new Scanner(System.in);
        l=Double.parseDouble(input.readLine());
        x=l/3;
        a=x*x*x;
        System.out.println(a);
      }
    } import java.io.*; io.* java import java.util.*; util.* java class Main
    {
      public static void main(String args[])throws IOException
      {
        double l,x,a;
        BufferedReader input=new BufferedReader(new InputStreamReader(System.in));
        Scanner sc =new Scanner(System.in);
        l=Double.parseDouble(input.readLine());
        x=l/3;
        a=x*x*x;
        System.out.println(a);
      }
    } Main public static void main(String args[])throws IOException
      {
        double l,x,a;
        BufferedReader input=new BufferedReader(new InputStreamReader(System.in));
        Scanner sc =new Scanner(System.in);
        l=Double.parseDouble(input.readLine());
        x=l/3;
        a=x*x*x;
        System.out.println(a);
      } main {
        double l,x,a;
        BufferedReader input=new BufferedReader(new InputStreamReader(System.in));
        Scanner sc =new Scanner(System.in);
        l=Double.parseDouble(input.readLine());
        x=l/3;
        a=x*x*x;
        System.out.println(a);
      } double l l x x a; a BufferedReader input=new BufferedReader(new InputStreamReader(System.in)); input new BufferedReader(new InputStreamReader(System.in)) Scanner sc =new Scanner(System.in); sc new Scanner(System.in) l=Double.parseDouble(input.readLine()) l Double.parseDouble(input.readLine()) Double.parseDouble Double input.readLine() input.readLine input x=l/3 x l/3 l 3 a=x*x*x a x*x*x x*x*x x x x System.out.println(a) System.out.println System.out System System.out a String args[] args
    import java.io.*;
	import java.util.*;
    class Main
    {
      public static void main(String args[])throws IOException
      {
        double l,x,a;
        BufferedReader input=new BufferedReader(new InputStreamReader(System.in));
        Scanner sc =new Scanner(System.in);
        l=Double.parseDouble(input.readLine());
        x=l/3;
        a=x*x*x;
        System.out.println(a);
      }
    }