import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int l = sc.nextInt();
        System.out.println(Math.pow(l / 3.0, 3));
    }
} import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int l = sc.nextInt();
        System.out.println(Math.pow(l / 3.0, 3));
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int l = sc.nextInt();
        System.out.println(Math.pow(l / 3.0, 3));
    } main {
        Scanner sc = new Scanner(System.in);
        int l = sc.nextInt();
        System.out.println(Math.pow(l / 3.0, 3));
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int l = sc.nextInt(); l sc.nextInt() sc.nextInt sc System.out.println(Math.pow(l / 3.0, 3)) System.out.println System.out System System.out Math.pow(l / 3.0, 3) Math.pow Math l / 3.0 l 3.0 3 String[] args args public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int l = sc.nextInt();
        System.out.println(Math.pow(l / 3.0, 3));
    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int l = sc.nextInt();
        System.out.println(Math.pow(l / 3.0, 3));
    }
} Main
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int l = sc.nextInt();
        System.out.println(Math.pow(l / 3.0, 3));
    }
}
