class Program
    {

        private const string PromptString = "Please enter a string :";
        private const string ConfirmPromptString = "Your enter the string is : \"{0}\"";
        private const string TabString = "\t\t\t";
        private const string FrequencyString = "The highest frequency in enter string is character '{0}',count is {1}";

        static void Main(string[] args)
        {
            while (true)
            {
                Console.WriteLine(PromptString);
                Console.WriteLine();
                Console.Write(TabString);

                string enterString = Console.ReadLine();

                Console.WriteLine();
                Console.WriteLine(ConfirmPromptString, enterString);
                Console.WriteLine();

                char highestFrequencyChar;
                int count;

                MethodOne(enterString, out highestFrequencyChar, out count);

                Console.WriteLine("MethodOne :");
                Console.WriteLine();
                Console.WriteLine(FrequencyString, highestFrequencyChar, count);
                Console.WriteLine();

                MethodTwo(enterString, out highestFrequencyChar, out count);
                
                Console.WriteLine("MethodTwo :");
                Console.WriteLine();
                Console.WriteLine(FrequencyString, highestFrequencyChar, count);
                Console.WriteLine();
            }
        }

        private static int MethodOne(string enterString, out char highestFrequencyChar, out int count)
        {
            IDictionary<char, int> dic = new Dictionary<char, int>();

            highestFrequencyChar = ' ';

            int max = 0;

            for (int i = 0, len = enterString.Length; i < len; i++)
            {
                if (dic.TryGetValue(enterString[i], out count))
                {
                    if (++dic[enterString[i]] > max)
                    {
                        max = dic[enterString[i]];
                        highestFrequencyChar = enterString[i];
                    }
                }
                else
                {
                    dic[enterString[i]] = 1;
                }
            }
            count = max;
            return 1;
        }


        private static int MethodTwo(string enterString, out char highestFrequencyChar, out int count)
        {
            highestFrequencyChar = ' ';
            count = 0;

            int tempCount;

            for (int i = 0, len = enterString.Length; i < len; i++)
            {
                if ((tempCount = len - enterString.Replace(enterString[i].ToString(), "").Length) > count)
                {
                    count = tempCount;
                    highestFrequencyChar = enterString[i];
                }
            }

            return 1;
        }
    }