ReverseTheSentence

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

namespace ReverseSentenceAndNotPunctoation
{
    class ReverseSentence
    {
        static void Main(string[] args)
        {
            string sentense = Console.ReadLine();

            Regex words = new Regex(@"([a-zA-Z]+)");
            Regex nonWords = new Regex(@"([^a-zA-Z]+)");

            MatchCollection allWords = words.Matches(sentense);
            MatchCollection allNonWords = nonWords.Matches(sentense);

            List<string> singleWords = new List<string>();
            List<string> singleNonWords = new List<string>();

            foreach (Match word in allWords)
            {
                singleWords.Add(word.Groups[1].ToString());
            }

            foreach (Match nonWord in allNonWords)
            {
                singleNonWords.Add(nonWord.Groups[1].ToString());
            }


            StringBuilder result = new StringBuilder();
            for (int i = singleWords.Count - 1, j = 0; i >= 0; i--, j++)
            {
                result.Append(singleWords[i]);
                result.Append(singleNonWords[j]);
            }

            Console.WriteLine(result);
        }
    }
}