the ordeal of sitting through it 
(ROOT (NP (NP (DT the) (NN ordeal)) (PP (IN of) (S (VP (VBG sitting) (PP (IN through) (NP (PRP it))))))))
(ROOT (NP (NP (DT ) (NN )) (PP (IN ) (S (VP (VBG ) (PP (IN ) (NP (PRP ))))))))