Join PDF Files based on Size

Hi I have PDF files in a folder that I want to join first based on the criteria on (10MB each).
What I am trying to achieve is if the file size reaches 10mb then it should create another file with the same name but add a counter to it? Please can anyone help? or if you have a sample workflow that would work for me too.

Eg: of filename -
1.) abc.pdf
Note: Some of my pdf files have attachments so I can not use merge pdf activity.

Invoke this below code , for checking the file size in Bytes

“Dim infoReader As System.IO.FileInfo = My.Computer.FileSystem.GetFileInfo( FilePath)
FileSize = infoReader.Length”