C ＃ enter a letter and judge its case

C# Enter a letter , Judge its case

using System;

namespace character
{
    
    class Program
    {
    
        static void Main(string[] args)
        {
    
            Console.WriteLine(" Please enter a letter :");
            char s = char.Parse(Console.ReadLine());
            if(s >= 'A' && s<= 'Z')
            {
    
                Console.WriteLine(s + " It's a capital letter ");
            }else if(s >= 'a' && s <= 'z')
            {
    
                Console.WriteLine(s + " It's a small letter ");
            }else
            {
    
                Console.WriteLine(s +" It's not a letter ");
            }
            Console.ReadKey();
        }
    }
}