import java.util.*;
import java.math.*;

public class Main {

  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    double l = sc.nextDouble();

    double x = l/3;
    double y = l/3;
    double z = l-x-y;

    System.out.println(x*y*z);

  }

} import java.util.*; util.* java import java.math.*; math.* java public class Main {

  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    double l = sc.nextDouble();

    double x = l/3;
    double y = l/3;
    double z = l-x-y;

    System.out.println(x*y*z);

  }

} Main public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    double l = sc.nextDouble();

    double x = l/3;
    double y = l/3;
    double z = l-x-y;

    System.out.println(x*y*z);

  } main {
    Scanner sc = new Scanner(System.in);
    double l = sc.nextDouble();

    double x = l/3;
    double y = l/3;
    double z = l-x-y;

    System.out.println(x*y*z);

  } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) double l = sc.nextDouble(); l sc.nextDouble() sc.nextDouble sc double x = l/3; x l/3 l 3 double y = l/3; y l/3 l 3 double z = l-x-y; z l-x-y l-x-y l x y System.out.println(x*y*z) System.out.println System.out System System.out x*y*z x*y*z x y z String[] args args public class Main {

  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    double l = sc.nextDouble();

    double x = l/3;
    double y = l/3;
    double z = l-x-y;

    System.out.println(x*y*z);

  }

} public class Main {

  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    double l = sc.nextDouble();

    double x = l/3;
    double y = l/3;
    double z = l-x-y;

    System.out.println(x*y*z);

  }

} Main
import java.util.*;
import java.math.*;

public class Main {

  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    double l = sc.nextDouble();

    double x = l/3;
    double y = l/3;
    double z = l-x-y;

    System.out.println(x*y*z);

  }

}
