an face-up think outside low holes maybe .
(ROOT_0 (S_0 (ATS_3 (NP_1 (DT_1 an) (NN_2 face-up)) (VP_4 (ATVP_4 (VB_0 think) (PP_1 (IN_1 outside) (NP_2 (JJ_1 low) (NNS_1 holes)))) (ADVP_0 (RB_0 maybe)))) (DOT_0 .)))