String Mix

StringMix.cs

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

namespace StringMix
{
    class Program
    {
        static void Main(string[] args)
        {
            // Provide args s1 and s2 for Mix method
            Mix("Are They HERE?", "yes, they are HEre");
            Console.ReadKey();
        }

        public static string Mix(string s1, string s2)
        {
            Console.WriteLine($"S1: {s1} - S2 {s2}");
            // initialize objects for each string
            Sentence s1Obj = new Sentence();
            Sentence s2Obj = new Sentence();
            List<KeyValuePair<string, string>> kvPairs = new List<KeyValuePair<string, string>>();
            Regex reg = new Regex(@"[a-z]");
            Match match = reg.Match("");

            foreach (var letter in s1)
            {
                match = reg.Match(letter.ToString());
                if (match.Success && !Int32.TryParse(letter.ToString(), out int num))
                {
                    if (s1Obj.letterCount.Where(x => x.Key == letter.ToString()).Count() == 0)
                    {
                        s1Obj.letterCount.Add(letter.ToString(), 1);
                        if (s2Obj.letterCount.Where(x => x.Key == letter.ToString()).Count() == 0)
                        {
                            s2Obj.letterCount.Add(letter.ToString(), 0);
                        }
                    }
                    else
                    {
                        s1Obj.letterCount[letter.ToString()]++;
                    }
                }
            }


            foreach (var letter in s2)
            {
                match = reg.Match(letter.ToString());
                if (match.Success && !Int32.TryParse(letter.ToString(), out int nums))
                {
                    if (s2Obj.letterCount.Where(x => x.Key == letter.ToString()).Count() == 0)
                    {
                        s2Obj.letterCount.Add(letter.ToString(), 1);
                        if (s1Obj.letterCount.Where(x => x.Key == letter.ToString()).Count() == 0)
                        {
                            s1Obj.letterCount.Add(letter.ToString(), 0);
                        }
                    }
                    else
                    {
                        s2Obj.letterCount[letter.ToString()]++;
                    }
                }

            }

            var answer = "";

            foreach (var item in s1Obj.letterCount)
            {
                if (s1Obj.letterCount[item.Key] > s2Obj.letterCount[item.Key] && s1Obj.letterCount[item.Key] > 1)
                {
                    var letters = "";
                    for (int i = 0; i <= s1Obj.letterCount[item.Key] - 1; i++)
                    {
                        letters += item.Key;
                    }
                    var kvp = new KeyValuePair<string, string>("1", letters);
                    kvPairs.Add(kvp);
                }
                else if (s1Obj.letterCount[item.Key] < s2Obj.letterCount[item.Key] && s2Obj.letterCount[item.Key] > 1)
                {
                    var letters = "";
                    for (int i = 0; i <= s2Obj.letterCount[item.Key] - 1; i++)
                    {
                        letters += item.Key;
                    }
                    var kvp = new KeyValuePair<string, string>("2", letters);
                    kvPairs.Add(kvp);
                }
                else if (s1Obj.letterCount[item.Key] == s2Obj.letterCount[item.Key] && s1Obj.letterCount[item.Key] > 1)
                {
                    var letters = "";
                    for (int i = 0; i <= s1Obj.letterCount[item.Key] - 1; i++)
                    {
                        letters += item.Key;
                    }
                    var kvp = new KeyValuePair<string, string>("3", letters);
                    kvPairs.Add(kvp);
                }
                else
                { }

            }
            if (kvPairs.Count > 0)
            {
                //key, length, value
                kvPairs = kvPairs.OrderBy(x => x.Value).OrderBy(x => x.Key).OrderByDescending(x => x.Value.Length).ToList<KeyValuePair<string, string>>();

                foreach (var item in kvPairs)
                {
                    answer += $"{item.Key}:{item.Value}/";
                }
                answer = answer.Remove(answer.Length - 1).Replace("3", "=");
            }

            return answer;
        }
    }

    public class Sentence
    {
        public string Name { get; set; }
        public Dictionary<string, int> letterCount { get; set; }

        public Sentence()
        {
            letterCount = new Dictionary<string, int>();
        }

    }
}








//Console.WriteLine(" - Letter Counts - \nString1:");
            //foreach (var set in s1Obj.letterCount)
            //{
            //    Console.WriteLine(set.Key + ":" + set.Value);
            //}
            //Console.WriteLine("\nString2:");
            //foreach (var set in s2Obj.letterCount)
            //{
            //    Console.WriteLine(set.Key + ":" + set.Value);
            //}