's undeniably hard to follow 
(ROOT (S (VP (VBZ 's) (ADJP (RB undeniably) (JJ hard) (SBAR (S (VP (TO to) (VP (VB follow)))))))))
(ROOT (S (VP (VBZ ) (ADJP (RB ) (JJ ) (SBAR (S (VP (TO ) (VP (VB )))))))))