for most movies , 84 minutes is short 
(ROOT (S (PP (IN for) (NP (JJS most) (NNS movies))) (, ,) (NP (CD 84) (NNS minutes)) (VP (VBZ is) (ADJP (JJ short)))))
(ROOT (S (PP (IN ) (NP (JJS ) (NNS ))) (, ) (NP (CD ) (NNS )) (VP (VBZ ) (ADJP (JJ )))))