How to add different headers in automatically created pages

private void button1_Click(object sender, EventArgs e)
        {
            //Create a new PDF document.
            PdfDocument doc = new PdfDocument();
 
            //Add section
            PdfSection section1 = doc.Sections.Add();
 
            //Add a page.
            PdfPage page = section1.Pages.Add();
 
            //Create a header and draw the image.
            RectangleF rect = new RectangleF(0, 0, doc.Pages[0].GetClientSize().Width, 50);
 
            //Initialize new instance for header
            PdfPageTemplateElement header = new PdfPageTemplateElement(rect);
 
            PdfImage image = new PdfBitmap("../../Data/logo.png");
 
            //Draw the image in the header.
            header.Graphics.DrawImage(image, new PointF(0, 0), new SizeF(200, 50));
 
            //Add the header at the top.
            section1.Template.Top = header;
 
            //Read RTF document.
            StreamReader reader = new StreamReader("../../Data/input.rtf", Encoding.ASCII);
 
            string text = reader.ReadToEnd();
 
            //Close reader
            reader.Close();
 
            //Convert it to metafile.
            PdfMetafile metafile = (PdfMetafile)PdfImage.FromRtf(text, page.GetClientSize().Width, PdfImageType.Metafile);
 
            PdfMetafileLayoutFormat format = new PdfMetafileLayoutFormat();
 
            // Set text to draw in first page only.
            format.Layout = PdfLayoutType.OnePage;
 
            //Draws image.
            metafile.Draw(page, 0, 50, format);
 
            //Create section to draw remaining content of text
            PdfSection subSection1 = doc.Sections.Add();
 
            //Add a page
            PdfPage subPage1 = subSection1.Pages.Add();
 
            //Set font
            PdfFont font = new PdfStandardFont(PdfFontFamily.Helvetica, 15);
 
            //Create a header and draw the string.
            PdfPageTemplateElement header1 = new PdfPageTemplateElement(rect);
 
            header1.Graphics.DrawString("Header demo", font, PdfBrushes.Red, new PointF(0, 0));
 
            //Add the header at the top.
            subSection1.Template.Top = header1;
 
            // Set the text to paginate and draw in all pages.
            format.Layout = PdfLayoutType.Paginate;
 
            // Drawing the text in the page
            metafile.Draw(subPage1, 0, 50, format);
 
            // Removing the first page since it is already printed with header
            subSection1.Pages.Remove(subSection1.Pages[0]);
 
            //Save and close the document.
            doc.Save("Output.pdf");
 
            doc.Close(true);
 
            //Open the saved pdf document
            System.Diagnostics.Process.Start("Output.pdf");
        }