static void Main(string[] args)
{
#region AbstractClasses
// Compile time error - Cant create instance from abstract classes
// User user = new User();
//User student = new Student() { Name ="Vaska"};
//User trainer = new Trainer();
//User assistant = new Assistant();
//Console.WriteLine(trainer.Age);
//student.SayHi();
#endregion
}
}