of a paint-by-numbers picture 
(ROOT (PP (IN of) (NP (DT a) (NML (NML (NN paint)) (HYPH -) (PP (IN by) (HYPH -) (NP (NNS numbers)))) (NN picture))))
(ROOT (PP (IN ) (NP (DT ) (NML (NML (NN )) (HYPH ) (PP (IN ) (HYPH ) (NP (NNS )))) (NN ))))