using System;
class ChooseSubject
{
	static void Main()
	{
		int i;
		string str;
		Console.WriteLine ("Please choose your favorite subjects:-1 is quit.");
		Console.WriteLine ("1.Chinese.");
		Console.WriteLine ("2.Maths.");
		Console.WriteLine ("3.English.");
		Console.WriteLine ("4.Physical.");
		Console.WriteLine ("-1 is quit.");
		do
		{
			str=Console.ReadLine ();
			i=Int32.Parse (str);
			switch(i)
			{
				case 1:
					Console.WriteLine ("You like chinese very much.");
					break;
				case 2:
					Console.WriteLine ("You like maths very much.");
					break;
				case 3:
					Console.WriteLine ("You like english very much.");
					break;
				case 4:
					Console.WriteLine ("You like physical very much.");
					break;
				case -1:
					break;
				default:
					Console.WriteLine ("I'm sorry.You can't choose this subject.");
					break;
			}
	
		}while(i!=-1);
		Console.WriteLine ("Byebye!");
	}
}