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

public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		int num = sc.nextInt();
		BigDecimal three = BigDecimal.valueOf(3);
		BigDecimal maxlength = BigDecimal.valueOf(num).divide(three, 9, BigDecimal.ROUND_DOWN);
		System.out.println(maxlength.pow(3));
		
	}
} import java.math.BigDecimal; BigDecimal java.math import java.util.ArrayList; ArrayList java.util import java.util.List; List java.util import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		int num = sc.nextInt();
		BigDecimal three = BigDecimal.valueOf(3);
		BigDecimal maxlength = BigDecimal.valueOf(num).divide(three, 9, BigDecimal.ROUND_DOWN);
		System.out.println(maxlength.pow(3));
		
	}
} Main public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		int num = sc.nextInt();
		BigDecimal three = BigDecimal.valueOf(3);
		BigDecimal maxlength = BigDecimal.valueOf(num).divide(three, 9, BigDecimal.ROUND_DOWN);
		System.out.println(maxlength.pow(3));
		
	} main {

		Scanner sc = new Scanner(System.in);
		int num = sc.nextInt();
		BigDecimal three = BigDecimal.valueOf(3);
		BigDecimal maxlength = BigDecimal.valueOf(num).divide(three, 9, BigDecimal.ROUND_DOWN);
		System.out.println(maxlength.pow(3));
		
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int num = sc.nextInt(); num sc.nextInt() sc.nextInt sc BigDecimal three = BigDecimal.valueOf(3); three BigDecimal.valueOf(3) BigDecimal.valueOf BigDecimal 3 BigDecimal maxlength = BigDecimal.valueOf(num).divide(three, 9, BigDecimal.ROUND_DOWN); maxlength BigDecimal.valueOf(num).divide(three, 9, BigDecimal.ROUND_DOWN) BigDecimal.valueOf(num).divide BigDecimal.valueOf(num) BigDecimal.valueOf BigDecimal num three 9 BigDecimal.ROUND_DOWN BigDecimal BigDecimal.ROUND_DOWN System.out.println(maxlength.pow(3)) System.out.println System.out System System.out maxlength.pow(3) maxlength.pow maxlength 3 String[] args args public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		int num = sc.nextInt();
		BigDecimal three = BigDecimal.valueOf(3);
		BigDecimal maxlength = BigDecimal.valueOf(num).divide(three, 9, BigDecimal.ROUND_DOWN);
		System.out.println(maxlength.pow(3));
		
	}
} public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		int num = sc.nextInt();
		BigDecimal three = BigDecimal.valueOf(3);
		BigDecimal maxlength = BigDecimal.valueOf(num).divide(three, 9, BigDecimal.ROUND_DOWN);
		System.out.println(maxlength.pow(3));
		
	}
} Main

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

public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		int num = sc.nextInt();
		BigDecimal three = BigDecimal.valueOf(3);
		BigDecimal maxlength = BigDecimal.valueOf(num).divide(three, 9, BigDecimal.ROUND_DOWN);
		System.out.println(maxlength.pow(3));
		
	}
}