var FilePath = @"test.in.txt";
            // var data = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
             using (FileStream fs = new FileStream(FilePath, FileMode.Open))
             {
                 using (BufferedStream bs = new BufferedStream(fs))
                 {
                     using (StreamReader textReader = new StreamReader(bs))
                     {
                         int maxLines = Int32.Parse(textReader.ReadLine());

                         int countLines = 0;
                         string line;
                         int dot = 1;
                         while ((line = textReader.ReadLine()) != null && countLines != maxLines + 1)
                         {
                             Console.WriteLine(dot);
                             dot++;
                             countLines++;

                             //  string key = line.Trim();
                             //  string value = textReader.ReadLine();
                             //  data.Add(key, value);
                         }
                     }
                 }

             }