rather less than the sum of its underventilated père-fils confrontations . 
(ROOT (ADJP (ADJP (RB rather) (JJR less)) (PP (IN than) (NP (NP (DT the) (NN sum)) (PP (IN of) (NP (PRP$ its) (JJ underventilated) (NML (NN père) (HYPH -) (NN fils)) (NNS confrontations))))) (. .)))
(ROOT (ADJP (ADJP (RB ) (JJR )) (PP (IN ) (NP (NP (DT ) (NN )) (PP (IN ) (NP (PRP$ ) (JJ ) (NML (NN ) (HYPH ) (NN )) (NNS ))))) (. )))