They finally had back under slept .
(ROOT_0 (S_0 (ATS_3 (ATS_1 (NP_1 (PRP_0 They)) (ADVP_0 (RB_0 finally))) (VP_3 (ATVP_3 (VBD_2 had) (PRT_0 (RP_0 back))) (PP_2 (IN_0 under) (NP_3 (NNP_1 slept))))) (DOT_0 .)))