import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        double n =  scanner.nextDouble();
        System.out.println(String.format("%.6f", Math.pow(n/3, 3)));
    }

} import java.util.*; util.* java public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        double n =  scanner.nextDouble();
        System.out.println(String.format("%.6f", Math.pow(n/3, 3)));
    }

} Main public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        double n =  scanner.nextDouble();
        System.out.println(String.format("%.6f", Math.pow(n/3, 3)));
    } main {
        Scanner scanner = new Scanner(System.in);
        double n =  scanner.nextDouble();
        System.out.println(String.format("%.6f", Math.pow(n/3, 3)));
    } Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) double n =  scanner.nextDouble(); n scanner.nextDouble() scanner.nextDouble scanner System.out.println(String.format("%.6f", Math.pow(n/3, 3))) System.out.println System.out System System.out String.format("%.6f", Math.pow(n/3, 3)) String.format String "%.6f" Math.pow(n/3, 3) Math.pow Math n/3 n 3 3 String[] args args public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        double n =  scanner.nextDouble();
        System.out.println(String.format("%.6f", Math.pow(n/3, 3)));
    }

} public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        double n =  scanner.nextDouble();
        System.out.println(String.format("%.6f", Math.pow(n/3, 3)));
    }

} Main
import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        double n =  scanner.nextDouble();
        System.out.println(String.format("%.6f", Math.pow(n/3, 3)));
    }

}
