iOS Question File Folders change with compile

Hi All

I am just wondering why is it that the "XXXXXX" part changes with every compile and how to work around that for determining previous file locations between updates

File.DirLibrary:
/var/mobile/Containers/Data/Application/XXXXXXXXXXXXXXXX/Library/

File.DirDocuments:
/var/mobile/Containers/Data/Application/XXXXXXXXXXXXXXX/Documents/

Thanks in advance
iCAB