using System;

    public class Person {

        string id;

        string name;

        public Person(string i, string n)

        {

            id = i; name = n;

        }

        public string getID()

        {

            return id;

        }

        public string getName()

        {

            return name;

        }

        public void displayDetails()

        {

            Console.WriteLine("ID       : {0}", id);

            Console.WriteLine("Name     : {0}", name);

        }

        public class Teacher : Person

        {

            double salary;

            public Teacher(string i, string n, double s)

                : base(i, n) { salary = s; }

            public Teacher(string i, string n)

                : base(i, n)

            {

                salary = 0;

            }

            public double getSalary() { return salary; }

            public void setSalary(double s)

            {

                if (s > 25000) Console.WriteLine("Salary over the limit!");

                else salary = s;

            }

            public void displayDetails()

            {

                Console.WriteLine("== TEACHER DETAILS ==");

                base.displayDetails();

                Console.WriteLine("Salary   : {0:c2}", salary);

            }

        }

        public class Student : Person

        {

            int birthYear;

​

            public Student(string i, string n, int b)

                : base(i, n) 

            {

                birthYear = b;

            }

​

            public int getBirthYear(){

                return birthYear;

            }

            public int getAge()

            {

                return (DateTime.Now.Year - birthYear);

            }

            public void displayDetails()

            {

                Console.WriteLine("== STUDENT DETAILS ==");

                base.displayDetails();

                Console.WriteLine("Birth Year: {0}", birthYear);

                Console.WriteLine("Age       : {0}", this.getAge());

            }

        }

        static void Main(string[] args)

        {

            Teacher tc1 = new Teacher("T003", "Mam");

            Teacher tc2 = new Teacher("T008", "Neena", 3000);

            Student st1 = new Student("S007", "Yoy", 2010);

            Student st2 = new Student("S009", "Peter", 2012);

            tc1.displayDetails();

            tc2.displayDetails();

            st1.displayDetails();

            st2.displayDetails();

        }

    }

​