How to obtain number of pages in a Crystal Reports .NET report

I have a web application in which I render one or more Crystal Reports and then merge them into one PDF. What I'd like to do is obtain the number of pages from one CrystalDecisions.CrystalReports.Engine.ReportDocument object then then set that value as a parameter in the subsequent ReportDocument in order to continue the page numbering correctly. Does the ReportDocument class expose a way of obtaining the number of pages? If not, are there other ways?

I am NOT using a Crystal Report Viewer.

I am using CrystalReports for Visual Studio 2010 and C# .NET 4.