import java.util.Scanner;

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

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