import java.util.*;
import java.math.BigDecimal;

public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        
        double L = sc.nextDouble();
        
        double a = L/3;
        double b = a*a*a;
        
        System.out.println(BigDecimal.valueOf(a*a*a).toPlainString());
        
    }
} import java.util.*; util.* java import java.math.BigDecimal; BigDecimal java.math public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        
        double L = sc.nextDouble();
        
        double a = L/3;
        double b = a*a*a;
        
        System.out.println(BigDecimal.valueOf(a*a*a).toPlainString());
        
    }
} Main public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        
        double L = sc.nextDouble();
        
        double a = L/3;
        double b = a*a*a;
        
        System.out.println(BigDecimal.valueOf(a*a*a).toPlainString());
        
    } main {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        
        double L = sc.nextDouble();
        
        double a = L/3;
        double b = a*a*a;
        
        System.out.println(BigDecimal.valueOf(a*a*a).toPlainString());
        
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) double L = sc.nextDouble(); L sc.nextDouble() sc.nextDouble sc double a = L/3; a L/3 L 3 double b = a*a*a; b a*a*a a*a*a a a a System.out.println(BigDecimal.valueOf(a*a*a).toPlainString()) System.out.println System.out System System.out BigDecimal.valueOf(a*a*a).toPlainString() BigDecimal.valueOf(a*a*a).toPlainString BigDecimal.valueOf(a*a*a) BigDecimal.valueOf BigDecimal a*a*a a*a*a a a a String[] args args public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        
        double L = sc.nextDouble();
        
        double a = L/3;
        double b = a*a*a;
        
        System.out.println(BigDecimal.valueOf(a*a*a).toPlainString());
        
    }
} public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        
        double L = sc.nextDouble();
        
        double a = L/3;
        double b = a*a*a;
        
        System.out.println(BigDecimal.valueOf(a*a*a).toPlainString());
        
    }
} Main
import java.util.*;
import java.math.BigDecimal;

public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        
        double L = sc.nextDouble();
        
        double a = L/3;
        double b = a*a*a;
        
        System.out.println(BigDecimal.valueOf(a*a*a).toPlainString());
        
    }
}
