PDF Mosaic: How to add PDF pages and how delete PDF pages

/*Description:This sample shows how to add and delete pages to/from PDF document */
 
using PDFMosaic;
using System;
 
namespace AddAndDeletePages
{
  class AddAndDeletePages
  {
    static void Main(string[] args)
    {
      PDFDocument document = new PDFDocument();
 
      // Create font and brush for drawing on page
      PDFFont font = new PDFFont(PDFStandardFont.Helvetica, 25);
      PDFBrush brush = new PDFSolidBrush();
 
      // Add a standart page sizes
      foreach(PDFPaperFormat pageSize in Enum.GetValues(typeof(PDFPaperFormat)))
      {
        // Append new standart size page to the document
        PDFPage page = new PDFPage(pageSize);
        page.Canvas.DrawString("The page format is " + pageSize, font, brush, 100, 100);
 
        // Add created page to page collection
        document.Pages.Add(page);
      }
 
      // Create new custom size page to the document
      PDFPage customSizePage = new PDFPage(800, 600);
      customSizePage.Canvas.DrawString("This is the custom page size. Width = 800. Height = 600.", font, brush, 100, 100);
      document.Pages.Add(customSizePage);
 
      // Save pdf document
      document.Save("AddAndDeletePages.pdf", true);
 
      // Open created document before
      PDFDocument document2 = new PDFDocument("AddAndDeletePages.pdf");
 
      // Delete all pages, which width > 500
      for(int i = document2.Pages.Count-1; i >= 0; --i)
      {
        if(document2.Pages[i].Width > 500)
          document2.Pages.Remove(i);
      }
 
      // Save modifed pdf document
      document2.Save("AddAndDeletePages2.pdf", true);
    }
  }
}