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

public class Main {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner scan = new Scanner(System.in);
		int L = scan.nextInt();

		BigDecimal a = new BigDecimal(String.valueOf(L));
		BigDecimal div = new BigDecimal("3.0");
		a = a.divide(div, 7, RoundingMode.DOWN);
		
		BigDecimal length = new BigDecimal(String.valueOf(a));
		BigDecimal ans = length.multiply(length);
		ans = ans.multiply(length);
		
		System.out.print(ans);
	}

} import java.math.BigDecimal; BigDecimal java.math import java.math.RoundingMode; RoundingMode java.math import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner scan = new Scanner(System.in);
		int L = scan.nextInt();

		BigDecimal a = new BigDecimal(String.valueOf(L));
		BigDecimal div = new BigDecimal("3.0");
		a = a.divide(div, 7, RoundingMode.DOWN);
		
		BigDecimal length = new BigDecimal(String.valueOf(a));
		BigDecimal ans = length.multiply(length);
		ans = ans.multiply(length);
		
		System.out.print(ans);
	}

} Main public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner scan = new Scanner(System.in);
		int L = scan.nextInt();

		BigDecimal a = new BigDecimal(String.valueOf(L));
		BigDecimal div = new BigDecimal("3.0");
		a = a.divide(div, 7, RoundingMode.DOWN);
		
		BigDecimal length = new BigDecimal(String.valueOf(a));
		BigDecimal ans = length.multiply(length);
		ans = ans.multiply(length);
		
		System.out.print(ans);
	} main {
		// TODO 自動生成されたメソッド・スタブ
		Scanner scan = new Scanner(System.in);
		int L = scan.nextInt();

		BigDecimal a = new BigDecimal(String.valueOf(L));
		BigDecimal div = new BigDecimal("3.0");
		a = a.divide(div, 7, RoundingMode.DOWN);
		
		BigDecimal length = new BigDecimal(String.valueOf(a));
		BigDecimal ans = length.multiply(length);
		ans = ans.multiply(length);
		
		System.out.print(ans);
	} Scanner scan = new Scanner(System.in); scan new Scanner(System.in) int L = scan.nextInt(); L scan.nextInt() scan.nextInt scan BigDecimal a = new BigDecimal(String.valueOf(L)); a new BigDecimal(String.valueOf(L)) BigDecimal div = new BigDecimal("3.0"); div new BigDecimal("3.0") a = a.divide(div, 7, RoundingMode.DOWN) a a.divide(div, 7, RoundingMode.DOWN) a.divide a div 7 RoundingMode.DOWN RoundingMode RoundingMode.DOWN BigDecimal length = new BigDecimal(String.valueOf(a)); length new BigDecimal(String.valueOf(a)) BigDecimal ans = length.multiply(length); ans length.multiply(length) length.multiply length length ans = ans.multiply(length) ans ans.multiply(length) ans.multiply ans length System.out.print(ans) System.out.print System.out System System.out ans String[] args args public class Main {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner scan = new Scanner(System.in);
		int L = scan.nextInt();

		BigDecimal a = new BigDecimal(String.valueOf(L));
		BigDecimal div = new BigDecimal("3.0");
		a = a.divide(div, 7, RoundingMode.DOWN);
		
		BigDecimal length = new BigDecimal(String.valueOf(a));
		BigDecimal ans = length.multiply(length);
		ans = ans.multiply(length);
		
		System.out.print(ans);
	}

} public class Main {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner scan = new Scanner(System.in);
		int L = scan.nextInt();

		BigDecimal a = new BigDecimal(String.valueOf(L));
		BigDecimal div = new BigDecimal("3.0");
		a = a.divide(div, 7, RoundingMode.DOWN);
		
		BigDecimal length = new BigDecimal(String.valueOf(a));
		BigDecimal ans = length.multiply(length);
		ans = ans.multiply(length);
		
		System.out.print(ans);
	}

} Main
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner scan = new Scanner(System.in);
		int L = scan.nextInt();

		BigDecimal a = new BigDecimal(String.valueOf(L));
		BigDecimal div = new BigDecimal("3.0");
		a = a.divide(div, 7, RoundingMode.DOWN);
		
		BigDecimal length = new BigDecimal(String.valueOf(a));
		BigDecimal ans = length.multiply(length);
		ans = ans.multiply(length);
		
		System.out.print(ans);
	}

}
