private void InsertRomanNumber(string value)
 {
     Textbox_1.SelectedText = value;
     Textbox_1.SelectionStart++;
     Textbox_1.SelectionLength = 0;
     Textbox_1.Focus();
     Ans = false;
 }
 public MainWindow()
 {
     InitializeComponent();
     Textbox_1.Focus();
 }