is not a bad movie , just mediocre . 
(ROOT (S (VP (VBZ is) (RB not) (NP (NP (DT a) (JJ bad) (NN movie)) (, ,) (ADJP (RB just) (JJ mediocre)))) (. .)))
(ROOT (S (VP (VBZ ) (RB ) (NP (NP (DT ) (JJ ) (NN )) (, ) (ADJP (RB ) (JJ )))) (. )))