import java.util.Scanner;

public class Main{
  public static void main(String[] args){
    Scanner scanner = new Scanner(System.in);
    int L = scanner.nextInt();
    double answer = 0;
    
    answer = Math.pow(L,3) / (double)27;
    System.out.println(answer);
  }
} import java.util.Scanner; Scanner java.util public class Main{
  public static void main(String[] args){
    Scanner scanner = new Scanner(System.in);
    int L = scanner.nextInt();
    double answer = 0;
    
    answer = Math.pow(L,3) / (double)27;
    System.out.println(answer);
  }
} Main public static void main(String[] args){
    Scanner scanner = new Scanner(System.in);
    int L = scanner.nextInt();
    double answer = 0;
    
    answer = Math.pow(L,3) / (double)27;
    System.out.println(answer);
  } main {
    Scanner scanner = new Scanner(System.in);
    int L = scanner.nextInt();
    double answer = 0;
    
    answer = Math.pow(L,3) / (double)27;
    System.out.println(answer);
  } Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) int L = scanner.nextInt(); L scanner.nextInt() scanner.nextInt scanner double answer = 0; answer 0 answer = Math.pow(L,3) / (double)27 answer Math.pow(L,3) / (double)27 Math.pow(L,3) Math.pow Math L 3 (double)27 System.out.println(answer) System.out.println System.out System System.out answer String[] args args public class Main{
  public static void main(String[] args){
    Scanner scanner = new Scanner(System.in);
    int L = scanner.nextInt();
    double answer = 0;
    
    answer = Math.pow(L,3) / (double)27;
    System.out.println(answer);
  }
} public class Main{
  public static void main(String[] args){
    Scanner scanner = new Scanner(System.in);
    int L = scanner.nextInt();
    double answer = 0;
    
    answer = Math.pow(L,3) / (double)27;
    System.out.println(answer);
  }
} Main
import java.util.Scanner;

public class Main{
  public static void main(String[] args){
    Scanner scanner = new Scanner(System.in);
    int L = scanner.nextInt();
    double answer = 0;
    
    answer = Math.pow(L,3) / (double)27;
    System.out.println(answer);
  }
}