's not a bad premise , just a bad movie 
(ROOT (S (VP (VBZ 's) (RB not) (NP (DT a) (JJ bad) (NN premise))) (, ,) (NP (RB just) (DT a) (JJ bad) (NN movie))))
(ROOT (S (VP (VBZ ) (RB ) (NP (DT ) (JJ ) (NN ))) (, ) (NP (RB ) (DT ) (JJ ) (NN ))))