a boulders of a muffled friend so was .
(ROOT_0 (S_0 (ATS_3 (ATS_1 (NP_1 (NP_6 (DT_0 a) (NNS_1 boulders)) (PP_0 (IN_1 of) (NP_6 (ATNP_1 (DT_0 a) (JJ_1 muffled)) (NN_1 friend)))) (ADVP_0 (RB_0 so))) (VP_3 (VBD_0 was))) (DOT_0 .)))