
import java.math.BigDecimal;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        double L = scanner.nextInt();

        System.out.println(BigDecimal.valueOf(Math.pow(L / 3.0, 3)).toPlainString());
    }
} import java.math.BigDecimal; BigDecimal java.math import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        double L = scanner.nextInt();

        System.out.println(BigDecimal.valueOf(Math.pow(L / 3.0, 3)).toPlainString());
    }
} Main public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        double L = scanner.nextInt();

        System.out.println(BigDecimal.valueOf(Math.pow(L / 3.0, 3)).toPlainString());
    } main {
        Scanner scanner = new Scanner(System.in);

        double L = scanner.nextInt();

        System.out.println(BigDecimal.valueOf(Math.pow(L / 3.0, 3)).toPlainString());
    } Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) double L = scanner.nextInt(); L scanner.nextInt() scanner.nextInt scanner System.out.println(BigDecimal.valueOf(Math.pow(L / 3.0, 3)).toPlainString()) System.out.println System.out System System.out BigDecimal.valueOf(Math.pow(L / 3.0, 3)).toPlainString() BigDecimal.valueOf(Math.pow(L / 3.0, 3)).toPlainString BigDecimal.valueOf(Math.pow(L / 3.0, 3)) BigDecimal.valueOf BigDecimal 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 scanner = new Scanner(System.in);

        double L = scanner.nextInt();

        System.out.println(BigDecimal.valueOf(Math.pow(L / 3.0, 3)).toPlainString());
    }
} public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        double L = scanner.nextInt();

        System.out.println(BigDecimal.valueOf(Math.pow(L / 3.0, 3)).toPlainString());
    }
} Main

import java.math.BigDecimal;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        double L = scanner.nextInt();

        System.out.println(BigDecimal.valueOf(Math.pow(L / 3.0, 3)).toPlainString());
    }
}
