overwhelmed by its lack of purpose 
(ROOT (VP (VBN overwhelmed) (PP (IN by) (NP (NP (PRP$ its) (NN lack)) (PP (IN of) (NP (NN purpose)))))))
(ROOT (VP (VBN ) (PP (IN ) (NP (NP (PRP$ ) (NN )) (PP (IN ) (NP (NN )))))))