is enough to give you brain strain 
(ROOT (S (VP (VBZ is) (ADJP (JJ enough) (S (VP (TO to) (VP (VB give) (NP (PRP you)) (NP (NN brain) (NN strain)))))))))
(ROOT (S (VP (VBZ ) (ADJP (JJ ) (S (VP (TO ) (VP (VB ) (NP (PRP )) (NP (NN ) (NN )))))))))