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

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		BigDecimal n = BigDecimal.valueOf(sc.nextDouble());
		sc.close();
		System.out.println(func(n));
	}

	public static BigDecimal func(BigDecimal n) {
		BigDecimal x = n.divide(BigDecimal.valueOf(3), MathContext.DECIMAL32);

		return x.multiply(x).multiply(x);
	}
} import java.math.BigDecimal; BigDecimal java.math import java.math.MathContext; MathContext java.math import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		BigDecimal n = BigDecimal.valueOf(sc.nextDouble());
		sc.close();
		System.out.println(func(n));
	}

	public static BigDecimal func(BigDecimal n) {
		BigDecimal x = n.divide(BigDecimal.valueOf(3), MathContext.DECIMAL32);

		return x.multiply(x).multiply(x);
	}
} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		BigDecimal n = BigDecimal.valueOf(sc.nextDouble());
		sc.close();
		System.out.println(func(n));
	} main {
		Scanner sc = new Scanner(System.in);
		BigDecimal n = BigDecimal.valueOf(sc.nextDouble());
		sc.close();
		System.out.println(func(n));
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) BigDecimal n = BigDecimal.valueOf(sc.nextDouble()); n BigDecimal.valueOf(sc.nextDouble()) BigDecimal.valueOf BigDecimal sc.nextDouble() sc.nextDouble sc sc.close() sc.close sc System.out.println(func(n)) System.out.println System.out System System.out func(n) func n String[] args args public static BigDecimal func(BigDecimal n) {
		BigDecimal x = n.divide(BigDecimal.valueOf(3), MathContext.DECIMAL32);

		return x.multiply(x).multiply(x);
	} func {
		BigDecimal x = n.divide(BigDecimal.valueOf(3), MathContext.DECIMAL32);

		return x.multiply(x).multiply(x);
	} BigDecimal x = n.divide(BigDecimal.valueOf(3), MathContext.DECIMAL32); x n.divide(BigDecimal.valueOf(3), MathContext.DECIMAL32) n.divide n BigDecimal.valueOf(3) BigDecimal.valueOf BigDecimal 3 MathContext.DECIMAL32 MathContext MathContext.DECIMAL32 return x.multiply(x).multiply(x); x.multiply(x).multiply(x) x.multiply(x).multiply x.multiply(x) x.multiply x x x BigDecimal n n public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		BigDecimal n = BigDecimal.valueOf(sc.nextDouble());
		sc.close();
		System.out.println(func(n));
	}

	public static BigDecimal func(BigDecimal n) {
		BigDecimal x = n.divide(BigDecimal.valueOf(3), MathContext.DECIMAL32);

		return x.multiply(x).multiply(x);
	}
} public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		BigDecimal n = BigDecimal.valueOf(sc.nextDouble());
		sc.close();
		System.out.println(func(n));
	}

	public static BigDecimal func(BigDecimal n) {
		BigDecimal x = n.divide(BigDecimal.valueOf(3), MathContext.DECIMAL32);

		return x.multiply(x).multiply(x);
	}
} Main
import java.math.BigDecimal;
import java.math.MathContext;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		BigDecimal n = BigDecimal.valueOf(sc.nextDouble());
		sc.close();
		System.out.println(func(n));
	}

	public static BigDecimal func(BigDecimal n) {
		BigDecimal x = n.divide(BigDecimal.valueOf(3), MathContext.DECIMAL32);

		return x.multiply(x).multiply(x);
	}
}
