using System;

​

namespace MyApplication

{

 public class Person 

  {

  protected int id;

    public string name,phone;

  public Person(int ID)

  {

    id = ID;

    Console.WriteLine(id);

  }

    public Person(int ID,string Name) : this(ID)

    {

        name=Name;

        Console.WriteLine(id+" "+name);

    }

    public Person(int ID,string Name,string Phone) : this(ID,Name)

    {

        phone=Phone;

        Console.WriteLine(id+" "+name+" "+phone);

    }

 }

    public class Student : Person 

     {

     public string Std;

     public Student(int ID,string Name) : base(ID)

     {

     name = Name;

     Console.WriteLine(id+" "+name);

     }

     public Student(int ID,string Name,string Phone) : base(ID,Name)

     {

     phone = Phone;

     Console.WriteLine(id+" "+name+" "+phone);

     }

     public Student(int ID,string Name,string Phone,string std) : base(ID,Name,Phone)

     {

     Std = std;

     Console.WriteLine(id+" "+name+" "+phone+" "+Std);

     }

     }

    public class xyz

    {

    static void Main(string[] args)

    {

      Person a = new Person(10,"deep","6354041276");

      Student b = new Student(1,"bhavy","6354041276","12");

    }

  }

}

​

​

​