using System;

namespace Example24
{
	/// <summary>
	/// Summary description for Class1.
	/// </summary>
	class Class1
	{
		/// <summary>
		/// The main entry point for the application.
		/// </summary>
		[STAThread]
		static void Main(string[] args)
		{
			int grade;
			char letterGrade = 'A';

			do 
			{
				Console.Write("Enter your grade (0 <= grade <= 100): ");
				grade = int.Parse(Console.ReadLine());
			} while ((grade < 0) || (grade > 100));

			switch (grade / 10)
			{
				case 10:
					Console.WriteLine("First in class");
					letterGrade = 'A';
					break;

				case 9:
					Console.WriteLine("Congratulations");
					letterGrade = 'A';
					break;

				case 8:
					Console.WriteLine("Very good");
					letterGrade = 'B';
					break;

				case 7:
					Console.WriteLine("Okay");
					letterGrade = 'C';
					break;

				case 6:
					Console.WriteLine("Work harder");
					letterGrade = 'D';
					break;

				case 5:
				case 4:
				case 3:
				case 2:
				case 1:
				case 0:
					Console.WriteLine("Fail!");
					letterGrade = 'F';
					break;

				default:
					Console.WriteLine("Not a recognizable grade");
					letterGrade = 'Z';
					break;
			}

			Console.WriteLine("Your grade was " + letterGrade);
		}
	}
}