import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
      Scanner sc = new Scanner(System.in);
      double l = sc.nextInt();
      double x = l/3;
      System.out.println(Math.pow(x,3));
    }
} import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
      Scanner sc = new Scanner(System.in);
      double l = sc.nextInt();
      double x = l/3;
      System.out.println(Math.pow(x,3));
    }
} Main public static void main(String[] args) {
      Scanner sc = new Scanner(System.in);
      double l = sc.nextInt();
      double x = l/3;
      System.out.println(Math.pow(x,3));
    } main {
      Scanner sc = new Scanner(System.in);
      double l = sc.nextInt();
      double x = l/3;
      System.out.println(Math.pow(x,3));
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) double l = sc.nextInt(); l sc.nextInt() sc.nextInt sc double x = l/3; x l/3 l 3 System.out.println(Math.pow(x,3)) System.out.println System.out System System.out Math.pow(x,3) Math.pow Math x 3 String[] args args public class Main {
    public static void main(String[] args) {
      Scanner sc = new Scanner(System.in);
      double l = sc.nextInt();
      double x = l/3;
      System.out.println(Math.pow(x,3));
    }
} public class Main {
    public static void main(String[] args) {
      Scanner sc = new Scanner(System.in);
      double l = sc.nextInt();
      double x = l/3;
      System.out.println(Math.pow(x,3));
    }
} Main
import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
      Scanner sc = new Scanner(System.in);
      double l = sc.nextInt();
      double x = l/3;
      System.out.println(Math.pow(x,3));
    }
}