How does "Available Offline" count files?

[TechDave88]

Where does Spotify get its "Available Offline" files from and how does it effect the 3,333 songs/device limit?

Let's say that I have a playlist with 10 songs, 4 of which are "Local Files" on my desktop, 

When I save the file for "Offline" listening on my iphone, does Spotify count the full 10 toward my 3,333 song/device limit, or only the 6 that it gets from the Spotify servers?

Would I have 3327 possible offline files left or 3323?

-Dave