using System;

public class Program

{

​

public enum PreferedContatWay { Sms, Email, Lms }

​

public class Student

{

    public int Id { get; set; }

    public PreferedContatWay ContactMethod { get; set; }

}

​

public class Notify

{

    ISendable _s;

    public Notify(ISendable s)

    {

        _s = s;

    }

​

}

​

public class MainProgram

{

    public List<Student> students;

    public MainProgram()

    {

        foreach (var student in students)

        {

            var factoredObj = FactoryObjecCreator(student);

            var notify = new Notify(factoredObj);

            notify.

        }

    }

​

    ISendable FactoryObjecCreator(Student student)

    => student.ContactMethod.ToString() switch

    {

        nameof(Email) => new Email(student),

        nameof(Sms) => new Email(student),

        nameof(Lms) => new Email(student),

        _ => throw new NotImplementedException()

    };

}

​

public interface ISendable

{

    public int Send(string message);

}

public class Sms : ISendable

{

    public Sms(Student student)

    {

​

    }

​

    public int Send(string message)

    {

        throw new NotImplementedException();

    }

}

​

public class Email : ISendable

{

    public Email(Student student)

    {

​

    }

​

    public int Send(string message)

    {

        throw new NotImplementedException();

    }

}

public class Lms : ISendable

{

    public Lms(Student student)

    {

​

    }

​

    public int Send(string message)

    {

        throw new NotImplementedException();

    }

}

}