import java.util.*;
class Main
{
  public static void main(String args[])
  {
    Scanner in=new Scanner(System.in);
    double L=in.nextDouble();
    double p=(double)(L/3);
    double k=p*p*p;
    System.out.println(k);
  }
} import java.util.*; util.* java class Main
{
  public static void main(String args[])
  {
    Scanner in=new Scanner(System.in);
    double L=in.nextDouble();
    double p=(double)(L/3);
    double k=p*p*p;
    System.out.println(k);
  }
} Main public static void main(String args[])
  {
    Scanner in=new Scanner(System.in);
    double L=in.nextDouble();
    double p=(double)(L/3);
    double k=p*p*p;
    System.out.println(k);
  } main {
    Scanner in=new Scanner(System.in);
    double L=in.nextDouble();
    double p=(double)(L/3);
    double k=p*p*p;
    System.out.println(k);
  } Scanner in=new Scanner(System.in); in new Scanner(System.in) double L=in.nextDouble(); L in.nextDouble() in.nextDouble in double p=(double)(L/3); p (double)(L/3) L 3 double k=p*p*p; k p*p*p p*p*p p p p System.out.println(k) System.out.println System.out System System.out k String args[] args
import java.util.*;
class Main
{
  public static void main(String args[])
  {
    Scanner in=new Scanner(System.in);
    double L=in.nextDouble();
    double p=(double)(L/3);
    double k=p*p*p;
    System.out.println(k);
  }
}