using System;

public class Program

{

    public class Person{

        public string Name {get; set;}

        public int Age {get; set;}

        public Person(string Name, int Age){

            this.Name = Name;

            this.Age = Age;

        }

        public virtual void DisplayDetails(){

            Console.WriteLine("This person is "+ Name +" and is " + Age + " years old");

        }

    }

    public class Student : Person{

        public int StudentId {get; set;}

        public Student(string Name, int Age, int StudentId) : base(Name, Age){

            this.StudentId = StudentId;

        }

        public override void DisplayDetails(){

        Console.WriteLine("This person is "+ Name +", is " + Age + " years old, and student Id number is " + StudentId +".");

        }

                      }

​

    public static void Main()

    {

    }

}