private void btnReadData_Click(object sender, RoutedEventArgs e)
        {
            OpenFileDialog openFile = new OpenFileDialog();

            if (openFile.ShowDialog() == false)
            {
                return;
            }
            using (StreamReader sr = new StreamReader(openFile.FileName, Encoding.Default, false))
            {
                int i = 0;
                while (!sr.EndOfStream && i < 5)
                {
                    string link = sr.ReadLine();
                    link += "/description/";
                    string htmlstr = HtmlHelper.GetResponseString(link);
                    string title   = RegualerHelper.GetTitle(htmlstr);
                    string content = RegualerHelper.GetContent(htmlstr);
                    link    = link.Replace("problems", "articles").Replace("/description/", "");
                    htmlstr = HtmlHelper.GetResponseString(link);
                    string solution = RegualerHelper.GetSolution(htmlstr);
                    ModelList.Add(new ProblemModel()
                    {
                        Title = title, Discrition = content, Solution = solution
                    });
                    i++;
                }
            }
        }
        private void btnRegex_Click(object sender, RoutedEventArgs e)
        {
            string inputstr = txtOutput.Text;

            //txtOutput.Text = RegualerHelper.GetAllMatches(inputstr, txtUrl.Text);
            txtOutput.Text = RegualerHelper.GetSolution(inputstr);
        }