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