using System;

​

public class Professor

{

    public string ProfessorName;

    private int _Age;

    public int Age

    {

        get

        {

            return _Age;

        }

        set

        {

            if (value < 18 || value > 70) _Age = 30;

            _Age = value;

        }

    }

​

    private string _Degree;

    public string Degree {

        get

        {

            return _Degree;

        }

        set

        {

            if ((value != "master") && value != "phd")

            {

                _Degree = "master";

            } else {

                _Degree = value;

            }

        }

    }

​

    public Professor()

    {

    }

}

​

​

public class Course

{

public string CourseName;

    private string _CourseID;

    public string CourseID {

        get

        {

            return _CourseID;

        }

        set

        {

            if (value.Length == 4)

            {

                _CourseID = value;

            } else {

                _CourseID = "";

            }

        }

    }

​

    private int _ClassCapacity;

    public int ClassCapacity {

        get

        {

            return _ClassCapacity;

        }

        set

        {

            if (value >= 1 && value <= 50){

                _ClassCapacity = value;

            } else if (value > 50) {

                _ClassCapacity = 50;

            } else if (value < 1) {

                _ClassCapacity = 1;

            }

        }

    }

​

    public Course()

    {

    }

}

​

public class Program

{

    public static void Main()

    {

        Professor T = new Professor();

        T.ProfessorName = "Tuna";

        T.Age = 99;

        Console.WriteLine(T.Age);

​

        Course CourseS308 = new Course();

        CourseS308.CourseID = "S308";

        CourseS308.CourseName = "C#";

        CourseS308.ClassCapacity = 21;

​

        Console.WriteLine("ProfessorName: {0}; Age: {1}", T.ProfessorName, T.Age);

        Console.WriteLine("CourseID: {0}; CourseName: {1}; ClassCapacity: {2}", CourseS308.CourseID, CourseS308.CourseName,CourseS308.ClassCapacity);

    }

}