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

public class Main {


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

	    BigDecimal result = execute(sc.nextLine());
        System.out.println(result.toPlainString());
    }

    public static BigDecimal execute(String value){
        BigDecimal totalLength = new BigDecimal(value);
        BigDecimal sideLength = totalLength.divide(BigDecimal.valueOf(3),7, RoundingMode.HALF_EVEN);
        return sideLength.multiply(sideLength).multiply(sideLength);
    }

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


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

	    BigDecimal result = execute(sc.nextLine());
        System.out.println(result.toPlainString());
    }

    public static BigDecimal execute(String value){
        BigDecimal totalLength = new BigDecimal(value);
        BigDecimal sideLength = totalLength.divide(BigDecimal.valueOf(3),7, RoundingMode.HALF_EVEN);
        return sideLength.multiply(sideLength).multiply(sideLength);
    }

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

	    BigDecimal result = execute(sc.nextLine());
        System.out.println(result.toPlainString());
    } main {
        Scanner sc = new Scanner(System.in);

	    BigDecimal result = execute(sc.nextLine());
        System.out.println(result.toPlainString());
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) BigDecimal result = execute(sc.nextLine()); result execute(sc.nextLine()) execute sc.nextLine() sc.nextLine sc System.out.println(result.toPlainString()) System.out.println System.out System System.out result.toPlainString() result.toPlainString result String[] args args public static BigDecimal execute(String value){
        BigDecimal totalLength = new BigDecimal(value);
        BigDecimal sideLength = totalLength.divide(BigDecimal.valueOf(3),7, RoundingMode.HALF_EVEN);
        return sideLength.multiply(sideLength).multiply(sideLength);
    } execute {
        BigDecimal totalLength = new BigDecimal(value);
        BigDecimal sideLength = totalLength.divide(BigDecimal.valueOf(3),7, RoundingMode.HALF_EVEN);
        return sideLength.multiply(sideLength).multiply(sideLength);
    } BigDecimal totalLength = new BigDecimal(value); totalLength new BigDecimal(value) BigDecimal sideLength = totalLength.divide(BigDecimal.valueOf(3),7, RoundingMode.HALF_EVEN); sideLength totalLength.divide(BigDecimal.valueOf(3),7, RoundingMode.HALF_EVEN) totalLength.divide totalLength BigDecimal.valueOf(3) BigDecimal.valueOf BigDecimal 3 7 RoundingMode.HALF_EVEN RoundingMode RoundingMode.HALF_EVEN return sideLength.multiply(sideLength).multiply(sideLength); sideLength.multiply(sideLength).multiply(sideLength) sideLength.multiply(sideLength).multiply sideLength.multiply(sideLength) sideLength.multiply sideLength sideLength sideLength String value value public class Main {


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

	    BigDecimal result = execute(sc.nextLine());
        System.out.println(result.toPlainString());
    }

    public static BigDecimal execute(String value){
        BigDecimal totalLength = new BigDecimal(value);
        BigDecimal sideLength = totalLength.divide(BigDecimal.valueOf(3),7, RoundingMode.HALF_EVEN);
        return sideLength.multiply(sideLength).multiply(sideLength);
    }

} public class Main {


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

	    BigDecimal result = execute(sc.nextLine());
        System.out.println(result.toPlainString());
    }

    public static BigDecimal execute(String value){
        BigDecimal totalLength = new BigDecimal(value);
        BigDecimal sideLength = totalLength.divide(BigDecimal.valueOf(3),7, RoundingMode.HALF_EVEN);
        return sideLength.multiply(sideLength).multiply(sideLength);
    }

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

public class Main {


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

	    BigDecimal result = execute(sc.nextLine());
        System.out.println(result.toPlainString());
    }

    public static BigDecimal execute(String value){
        BigDecimal totalLength = new BigDecimal(value);
        BigDecimal sideLength = totalLength.divide(BigDecimal.valueOf(3),7, RoundingMode.HALF_EVEN);
        return sideLength.multiply(sideLength).multiply(sideLength);
    }

}
