one of - not working in search

I'm trying to compile a list of document names. These documents can have either of 2 classes. I've tried to use "one of" in the advanced search, but the field doesn't allow me to add a semicolon to add multiple classes.

I'm also unable to add a comma, or nay other characters to use as a delimiter.

I need to find documents with class "A" OR "B"

How can I accomplish this?