Access to the path is denied.

ExtractPages("E:\\Input\\PO_1_14101056-918476_20150911.pdf", "E:\\Output", 1, 2);

 public void ExtractPages(string sourcePdfPath, string outputPdfPath, int startPage, int endPage)
        {
            PdfReader reader = null;
            Document sourceDocument = null;
            PdfCopy pdfCopyProvider = null;
            PdfImportedPage importedPage = null;

            try
            {
                // Intialize a new PdfReader instance with the contents of the source Pdf file:
                reader = new PdfReader(sourcePdfPath);

                // For simplicity, I am assuming all the pages share the same size
                // and rotation as the first page:
                sourceDocument = new Document(reader.GetPageSizeWithRotation(startPage));

                // Initialize an instance of the PdfCopyClass with the source 
                // document and an output file stream:
                pdfCopyProvider = new PdfCopy(sourceDocument,
                    new System.IO.FileStream(outputPdfPath, System.IO.FileMode.Create));

                sourceDocument.Open();

                // Walk the specified range and add the page copies to the output file:
                for (int i = startPage; i <= endPage; i++)
                {
                    importedPage = pdfCopyProvider.GetImportedPage(reader, i);
                    pdfCopyProvider.AddPage(importedPage);
                }
                sourceDocument.Close();
                reader.Close();
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }