Worm Ipsum

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace WormIpsum
{
    class WormIpsum
    {
        static void Main(string[] args)
        {
            var input = Console.ReadLine();

            while (input!= "Worm Ipsum")
            {
                var inputToCkeck = input.Split(new char[] { '.' }, StringSplitOptions.RemoveEmptyEntries);

                if (!Char.IsUpper(input[0]) || inputToCkeck.Length!=1)
                {
                    input = Console.ReadLine();
                    continue;
                }

                var inputArgs = input.Split(new char[] { ' ', ',','.' }, StringSplitOptions.RemoveEmptyEntries);

                foreach (var word in inputArgs)
                {
                    int maxCount = 0;
                    string maxWord = "";
                    var maxChar = ' ';

                    for (int i = 0; i < word.Length-1; i++)
                    {
                        int currentCount = 0;
                        char currentChar = word[i];
                        int index = word.IndexOf(currentChar);

                        while (index!=-1)
                        {
                            currentCount += 1;

                            if (currentCount>maxCount)
                            {
                                maxCount = currentCount;
                                maxWord = word;
                                maxChar = currentChar;
                            }

                            index = word.IndexOf(currentChar, index+1);
                        }

                        if (maxCount >= 2)
                        {
                            input = input.Replace(maxWord, new string(maxChar, maxWord.Length));
                        }
                    }
                }
                Console.WriteLine(input);
                input = Console.ReadLine();
            }
        }
    }
}