using System;

public class Program

{

    public static void Main()

    {

        Console.Write("Enter a  grade ");

​

            var c = double.Parse(Console.ReadLine());

            if (c < 100)

                Console.WriteLine("It's less than 100");

            else if (c >= 100 && c <= 200)

                Console.WriteLine("It's between 100 and 200 ");

            else if (c > 200)

                Console.WriteLine(" It's greater than 200");

​

            Console.Read();

​

    }

}