They let a guy stepping fingers , calculations .
(ROOT_0 (S_0 (ATS_3 (NP_1 (PRP_0 They)) (VP_4 (VBD_0 let) (NP_3 (ATNP_0 (NP_4 (NP_5 (DT_0 a) (NN_2 guy)) (NP_6 (VBG_0 stepping) (NNS_0 fingers))) (COMMA_0 ,)) (NNS_0 calculations)))) (DOT_0 .)))