Hopefully I've uploaded the circuit properly
Using an apostrophe to denote the over-bar (Not), "+" is or, and "." is and, I wrote the initial circuit as:
r = (p'.(p.q).q)'
which I then simplified as follows:
r = p'' + (p.q)' + q'
= p + p' + q + q'
However, I'm not convinced this is correct. Help please.