using System;
using System.IO;
using System.Linq;
using System.Text;

namespace _01._Even_Lines
{
    class StartUp
    {
        static void Main(string[] args)
        {
            StreamReader streamReader = new StreamReader("./text.txt");

            int counter = 0;

            while (!streamReader.EndOfStream)
            {
                string line = streamReader.ReadLine();

                if(line == null)
                {
                    break;
                }

                if(counter % 2 == 0)
                {
                    char[] charsToReplace = new char[] { '-', ',', '.', '!', '?' };

                    line = ReplaceChars(charsToReplace, '@', line);
                    line = ReverseWordsOrder(line);

                    Console.WriteLine(line);
                }

                counter++;
            }
        }

        private static string ReverseWordsOrder(string line)
        {
            line = String.Join(" ", line.Split(" ").Reverse());
            return line;
        }

        static string ReplaceChars(char[] charsToReplace, char replacement, string str)
        {
            StringBuilder sb = new StringBuilder();

            for (int i = 0; i < str.Length; i++)
            {
                if (charsToReplace.Contains(str[i]))
                {
                    sb.Append(replacement);
                }
                else
                {
                    sb.Append(str[i]);
                }
            }

            return sb.ToString().TrimEnd();
        }
    }
}