hours of material to discuss 
(ROOT (NP (NP (NP (NNS hours)) (PP (IN of) (NP (NN material)))) (SBAR (S (VP (TO to) (VP (VB discuss)))))))
(ROOT (NP (NP (NP (NNS )) (PP (IN ) (NP (NN )))) (SBAR (S (VP (TO ) (VP (VB )))))))