import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		double l = sc.nextDouble();
		
		double vol = Math.pow(l / 3.0, 3);
		System.out.printf("%8f\n", vol);
	}
} import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		double l = sc.nextDouble();
		
		double vol = Math.pow(l / 3.0, 3);
		System.out.printf("%8f\n", vol);
	}
} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		double l = sc.nextDouble();
		
		double vol = Math.pow(l / 3.0, 3);
		System.out.printf("%8f\n", vol);
	} main {
		Scanner sc = new Scanner(System.in);
		double l = sc.nextDouble();
		
		double vol = Math.pow(l / 3.0, 3);
		System.out.printf("%8f\n", vol);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) double l = sc.nextDouble(); l sc.nextDouble() sc.nextDouble sc double vol = Math.pow(l / 3.0, 3); vol Math.pow(l / 3.0, 3) Math.pow Math l / 3.0 l 3.0 3 System.out.printf("%8f\n", vol) System.out.printf System.out System System.out "%8f\n" vol String[] args args public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		double l = sc.nextDouble();
		
		double vol = Math.pow(l / 3.0, 3);
		System.out.printf("%8f\n", vol);
	}
} public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		double l = sc.nextDouble();
		
		double vol = Math.pow(l / 3.0, 3);
		System.out.printf("%8f\n", vol);
	}
} Main
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		double l = sc.nextDouble();
		
		double vol = Math.pow(l / 3.0, 3);
		System.out.printf("%8f\n", vol);
	}
}
