using System;

using System.Collections.Generic;

using System.Collections.ObjectModel;

​

public class Program

{

    public static void Main(String[] args)

    {

        var ram= new Student("Ram","Krishnan",20);

        var srini=new Student("Srini","Patteri",21);

        var preeti=new Student("Preeti","Roy",20);

        var rina=new Teacher("Rena","Nair",32);

        var ccourse=new Course("Programming with C#")

        {

            students=new Collection<Student>{ram,srini,preeti},

                teachers=new Collection<Teacher>{rina}

        };

        var ddegree=new Degree("Bachelor")

        {

            course=ccourse

        };

        var uProgram=new UProgram("Information Technology")

        {

            degree=ddegree

        };

        Console.WriteLine(uProgram);

        Console.WriteLine(ddegree);

        int ccount=Student.Count();

        Console.WriteLine("{0} students are currently enrolled",ccount);

    }

​

    public class UProgram

    {

        public string Name{get;private set;}

        public Degree degree{get;set;}

        public UProgram(String name)

        {

            this.Name=name;

        }

        public override string ToString()

        {

            return "The "+ Name+ " degree contains the course "+ degree.Name;

        }

    }

    public class Degree

    {

        public string Name{get;private set;}

        public Course course{get;set;}

        public Degree(string name)

        {

            this.Name=name;

        }

        public override string ToString()

        {

            return "The "+ Name+ " degree contains the course "+ course.Name;

        }

​

    }

    public class Course

    {

        public string Name{get; private set;}

        public IEnumerable<Student> students{get;set;}

        public IEnumerable<Teacher> teachers{get;set;}

        public Course(string name)

        {

            this.Name=name;

        }

    }

    public class Student

    {

        public string FirstName{get;set;}

        public string LastName{get;set;}

        public int Age {get;set;}

        public static int count=0;

        public Student(string first,string last,int age)

        {

            this.FirstName=first;

            this.LastName=last;

            this.Age=age;

            count++;

        }

        public static int Count()

    {

        return count;

    }

    }

    public class Teacher

    {

        public string FirstName{get;set;}

        public string LastName{get;set;}

        public int Age {get;set;}

        public Teacher(string first,string last,int age)

        {

            this.FirstName=first;

            this.LastName=last;

            this.Age=age;

        }

        }}