to a classes of hill dirt , <apostrophe><apostrophe>
(ROOT_0 (S_0 (ATS_2 (PP_2 (TO_0 to) (NP_3 (NP_6 (DT_0 a) (NNS_1 classes)) (PP_0 (IN_1 of) (NP_2 (NN_2 hill) (NN_3 dirt))))) (COMMA_0 ,)) (APOSTROPHE_0 <apostrophe><apostrophe>)))