import java.util.Scanner;

public class Main {

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

        final double L = sc.nextDouble();

        System.out.printf("%12f\n", L / 3.0 * L / 3.0 * L / 3.0);
    }
} import java.util.Scanner; Scanner java.util public class Main {

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

        final double L = sc.nextDouble();

        System.out.printf("%12f\n", L / 3.0 * L / 3.0 * L / 3.0);
    }
} Main public static void main(String[] args) {
        final Scanner sc = new Scanner(System.in);

        final double L = sc.nextDouble();

        System.out.printf("%12f\n", L / 3.0 * L / 3.0 * L / 3.0);
    } main {
        final Scanner sc = new Scanner(System.in);

        final double L = sc.nextDouble();

        System.out.printf("%12f\n", L / 3.0 * L / 3.0 * L / 3.0);
    } final Scanner sc = new Scanner(System.in); sc new Scanner(System.in) final double L = sc.nextDouble(); L sc.nextDouble() sc.nextDouble sc System.out.printf("%12f\n", L / 3.0 * L / 3.0 * L / 3.0) System.out.printf System.out System System.out "%12f\n" L / 3.0 * L / 3.0 * L / 3.0 L / 3.0 * L / 3.0 * L L / 3.0 * L / 3.0 L / 3.0 * L L / 3.0 L 3.0 L 3.0 L 3.0 String[] args args public class Main {

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

        final double L = sc.nextDouble();

        System.out.printf("%12f\n", L / 3.0 * L / 3.0 * L / 3.0);
    }
} public class Main {

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

        final double L = sc.nextDouble();

        System.out.printf("%12f\n", L / 3.0 * L / 3.0 * L / 3.0);
    }
} Main
import java.util.Scanner;

public class Main {

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

        final double L = sc.nextDouble();

        System.out.printf("%12f\n", L / 3.0 * L / 3.0 * L / 3.0);
    }
}
