Compare 2 strings by ignoring the case

Check for case insensitive match for the word BAR1 to BAR99

i.e. possible list of matches in this range are:

BAR1, bar1, BAR2,BAR3,BAR10,...BAR99,BaR99

static void IsMatchFound()
        {
            string pattern = @"^BAR([1-99]{1,2}|10|20|30|40|50|60|70|80|90)$";
            Console.WriteLine("Enter input:");
            string input = Console.ReadLine();
            if (input == "C")
            {
                Console.Clear();
            }
            Match result = Regex.Match(input, pattern, RegexOptions.Compiled | RegexOptions.IgnoreCase);
            if (result.Success)
            {

                Console.WriteLine("Valid");
            }
            else
            {
                Console.WriteLine("Invalid");
            }
        }​