he back watched up with the black wall .
(ROOT_0 (S_0 (ATS_3 (ATS_1 (NP_1 (PRP_1 he)) (ADVP_0 (RB_0 back))) (VP_3 (ATVP_3 (VBD_2 watched) (PRT_0 (RP_0 up))) (PP_2 (IN_0 with) (NP_3 (ATNP_1 (DT_0 the) (JJ_1 black)) (NN_1 wall))))) (DOT_0 .)))