using System;

namespace AbstractAndInterface

{

class Program

{

static void Main(string[] args)

{

Person employee = new Employee();

Person student = new Student();

employee.Say();

student.Say();

Console.ReadKey();

}

}

abstract class Person

{

protected string _name;

protected DateTime _birthDate;

public virtual void Say()

{

Console.WriteLine("Person is saying....");

}

public abstract void Work();

}

class Employee : Person

{

private float _salary;

public override void Say()

{

Console.WriteLine("Employee is saying....");

}

public override void Work()

{

Console.WriteLine("Employee is work....");

}

}

class Student : Person

{

private float _mark;

public override void Work()

{

Console.WriteLine("Student is work....");

}

}

}