a question for philosophers , not filmmakers 
(ROOT (NP (NP (DT a) (NN question)) (PP (IN for) (NP (NP (NNS philosophers)) (, ,) (RB not) (NP (NNS filmmakers))))))
(ROOT (NP (NP (DT ) (NN )) (PP (IN ) (NP (NP (NNS )) (, ) (RB ) (NP (NNS ))))))