using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        class Student

    {

        public static int StudentCount;

        public string firstName;

        public string lastName;

        public string grade;

​

    {

        Student.StudentCount++;

        firstStudent.firstName = "John";

        firstStudent.lastName = "Smith";

        firstStudent.grade = "six";

        secondStudent.firstName = "Tom";

        secondStudent.lastName = "Thumb";

        secondStudent.grade = "two";

        Console.WriteLine(firstStudent.firstName);

        Console.WriteLine(secondStudent.firstName);

        Console.WriteLine(Student.StudentCount);

    }

}

    }

}

​