import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;
/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

/**
 *
 * @author wnqmw
 */
public class Main {
    public static void main(String args[]) throws IOException {
        BufferedReader kb = new BufferedReader(new InputStreamReader(System.in));
        
        double dim = Double.parseDouble(kb.readLine());
        
        double side = dim/3;
        System.out.println(Math.pow(side, 3));
    }
} import java.io.BufferedReader; BufferedReader java.io import java.io.IOException; IOException java.io import java.io.InputStreamReader; InputStreamReader java.io import java.util.StringTokenizer; StringTokenizer java.util public class Main {
    public static void main(String args[]) throws IOException {
        BufferedReader kb = new BufferedReader(new InputStreamReader(System.in));
        
        double dim = Double.parseDouble(kb.readLine());
        
        double side = dim/3;
        System.out.println(Math.pow(side, 3));
    }
} Main public static void main(String args[]) throws IOException {
        BufferedReader kb = new BufferedReader(new InputStreamReader(System.in));
        
        double dim = Double.parseDouble(kb.readLine());
        
        double side = dim/3;
        System.out.println(Math.pow(side, 3));
    } main {
        BufferedReader kb = new BufferedReader(new InputStreamReader(System.in));
        
        double dim = Double.parseDouble(kb.readLine());
        
        double side = dim/3;
        System.out.println(Math.pow(side, 3));
    } BufferedReader kb = new BufferedReader(new InputStreamReader(System.in)); kb new BufferedReader(new InputStreamReader(System.in)) double dim = Double.parseDouble(kb.readLine()); dim Double.parseDouble(kb.readLine()) Double.parseDouble Double kb.readLine() kb.readLine kb double side = dim/3; side dim/3 dim 3 System.out.println(Math.pow(side, 3)) System.out.println System.out System System.out Math.pow(side, 3) Math.pow Math side 3 String args[] args public class Main {
    public static void main(String args[]) throws IOException {
        BufferedReader kb = new BufferedReader(new InputStreamReader(System.in));
        
        double dim = Double.parseDouble(kb.readLine());
        
        double side = dim/3;
        System.out.println(Math.pow(side, 3));
    }
} public class Main {
    public static void main(String args[]) throws IOException {
        BufferedReader kb = new BufferedReader(new InputStreamReader(System.in));
        
        double dim = Double.parseDouble(kb.readLine());
        
        double side = dim/3;
        System.out.println(Math.pow(side, 3));
    }
} Main
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;
/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

/**
 *
 * @author wnqmw
 */
public class Main {
    public static void main(String args[]) throws IOException {
        BufferedReader kb = new BufferedReader(new InputStreamReader(System.in));
        
        double dim = Double.parseDouble(kb.readLine());
        
        double side = dim/3;
        System.out.println(Math.pow(side, 3));
    }
}
