internal static void Main(string[] args)
{
Student s = new Student();
Teacher t = new Teacher();
s.failedHandler += t.RemindFailure;
s.Grade = 0;
}
static void Main(string[] args)
{
string sub;
Person p1 = new Person();
p1.Message();
Student s1 = new Student();
s1.SetAge(21);
s1.Message();
s1.ShowAge();
Teacher t1 = new Teacher();
t1.SetAge(30);
t1.Message();
t1.ShowAge();
Console.WriteLine("Enter the subject:");
sub = Console.ReadLine();
t1.SetSub(sub);
t1.Explain();
Console.Read();
}