static void Main(string[] args)
{
Student s1 = new Student("홍길동", 20, 201601);
s1.PrintAll();
Student s2 = new Student("홍길순", 201602);
s2.PrintAll();
Student s3 = new Student("나맹구");
s3.PrintAll();
Student s4 = new Student();
s4.PrintAll();
Console.WriteLine();
Teacher t1 = new Teacher("일강사", 30, "C#");
t1.PrintAll();
Teacher t2 = new Teacher("이강사", "C++");
t2.PrintAll();
Teacher t3 = new Teacher("삼강사");
t3.PrintAll();
Teacher t4 = new Teacher();
t4.PrintAll();
Console.WriteLine();
Employee e1 = new Employee("일직원", 25, 'A');
e1.PrintAll();
Employee e2 = new Employee("이직원", 'B');
e2.PrintAll();
Employee e3 = new Employee("삼직원");
e3.PrintAll();
Employee e4 = new Employee();
e4.PrintAll();
}
