it leave this classes , , kids to single calculations .
(ROOT_0 (S_0 (ATS_3 (NP_0 (PRP_1 it)) (VP_2 (ATVP_4 (VB_0 leave) (NP_2 (ATNP_2 (ATNP_2 (NP_6 (DT_0 this) (NNS_1 classes)) (COMMA_0 ,)) (COMMA_0 ,)) (NNS_1 kids))) (PP_2 (TO_0 to) (NP_3 (JJ_1 single) (NNS_0 calculations))))) (DOT_0 .)))