using System;

public class Program

{

    public static void Main()

    { 

        for (;;)

        {

        Console.WriteLine("Please enter your score:");

        int caseSwitch = int.Parse(Console.ReadLine());

        switch (caseSwitch)

        {case 0:

                Console.WriteLine("Graded: H");

                Console.WriteLine("Not specified");

                break;

         case 1:

         case 2:

                Console.WriteLine("Graded: G");

                Console.WriteLine("Very poor.");

                 break;

         case 3:

         case 4:

         case 5:

                 Console.WriteLine("Graded: F");

                Console.WriteLine("Poor.");

                 break;

         case 6:

         case 7:

         case 8:

                 Console.WriteLine("Graded: E");

                Console.WriteLine("Weak.");

                 break;

         case 9:

         case 10:

         case 11:

                Console.WriteLine("Graded: D");

                Console.WriteLine("Satisfactory.");

                 break; 

         case 12:

         case 13:

         case 14:

                Console.WriteLine("Graded: C");

                Console.WriteLine("Good.");

                 break;

         case 15:

         case 16:

         case 17:

                Console.WriteLine("Graded: B");

                Console.WriteLine("Very good.");

                 break;

         case 18:

         case 19:

         case 20:

         case 21:

         case 22:

                Console.WriteLine("Graded: A");

                Console.WriteLine("Excellent.");

                 break;

        default:

                Console.WriteLine("An unexpected value " + caseSwitch);

                Console.WriteLine("You entered a different number");

                break;

        }

        }

    }

}