using System;

public class Program

{

    public static void Main()

    {

     int size;

         char choice = 'Y';

​

            while ( choice != 'N')

            {

                if (choice == 'Y')

                {

                    Console.WriteLine("Input the number of Students: ");

                    size = Convert.ToInt32(Console.ReadLine());

                    Findlab(size);

​

                    Console.WriteLine("Want to check again?[Y/N]");

                    choice = Convert.ToChar(Console.ReadLine());

                }

               if ( choice == 'N')

                {

                    Console.WriteLine("Thanks for using the program !");

                }

            }

            Console.ReadLine();

        }

        static void Findlab(int size)

        {

            double result = size * 1.5;

            if (result <= 30)

            {

                Console.WriteLine("Room 1A");

                Console.WriteLine("Room 1B");

                Console.WriteLine("Room 1C");

            }

            else if ( result <= 50)

            {

                Console.WriteLine("Room 1B");

                Console.WriteLine("Room 1C");

            }

            else if (result <= 80)

            {

                Console.WriteLine("Room 1C");

            }

            else 

            {

                Console.WriteLine("Therse are no available rooms !");

            }

    }

}