using System;

public class Program

{

    public static void Main()

    {

        // nhap chu cai in nguyen am

        char kytu;

        Console.WriteLine("Nhap vao 1 ky tu bat ky");

        kytu=Convert.ToChar(Console.ReadLine());

        kytu=char.ToLower(kytu);

        switch(kytu)

        {

            case 'a':   case 'e':   case 'i':   case 'o':

            case 'u':Console.Write("Ky tu tren la nguyen am");break;

            default :   Console.Write("Ky tu tren la phu am");break;

        }

    }};