import java.util.*;
public class Main  
{ 
    
    public static void main(String[] args) 
    { 
        Scanner sc =new Scanner(System.in);
        double N = sc.nextDouble();
        N = N/3;
        double d = Math.pow(N,3);
      	System.out.println(d);
    }
}  import java.util.*; util.* java public class Main  
{ 
    
    public static void main(String[] args) 
    { 
        Scanner sc =new Scanner(System.in);
        double N = sc.nextDouble();
        N = N/3;
        double d = Math.pow(N,3);
      	System.out.println(d);
    }
} Main public static void main(String[] args) 
    { 
        Scanner sc =new Scanner(System.in);
        double N = sc.nextDouble();
        N = N/3;
        double d = Math.pow(N,3);
      	System.out.println(d);
    } main { 
        Scanner sc =new Scanner(System.in);
        double N = sc.nextDouble();
        N = N/3;
        double d = Math.pow(N,3);
      	System.out.println(d);
    } Scanner sc =new Scanner(System.in); sc new Scanner(System.in) double N = sc.nextDouble(); N sc.nextDouble() sc.nextDouble sc N = N/3 N N/3 N 3 double d = Math.pow(N,3); d Math.pow(N,3) Math.pow Math N 3 System.out.println(d) System.out.println System.out System System.out d String[] args args public class Main  
{ 
    
    public static void main(String[] args) 
    { 
        Scanner sc =new Scanner(System.in);
        double N = sc.nextDouble();
        N = N/3;
        double d = Math.pow(N,3);
      	System.out.println(d);
    }
} public class Main  
{ 
    
    public static void main(String[] args) 
    { 
        Scanner sc =new Scanner(System.in);
        double N = sc.nextDouble();
        N = N/3;
        double d = Math.pow(N,3);
      	System.out.println(d);
    }
} Main
import java.util.*;
public class Main  
{ 
    
    public static void main(String[] args) 
    { 
        Scanner sc =new Scanner(System.in);
        double N = sc.nextDouble();
        N = N/3;
        double d = Math.pow(N,3);
      	System.out.println(d);
    }
} 