They let not stronger of that giggles .
(ROOT_0 (S_0 (ATS_3 (NP_1 (PRP_0 They)) (VP_4 (ATVP_3 (VBD_0 let) (NP_6 (RB_1 not) (JJR_0 stronger))) (PP_1 (IN_1 of) (NP_0 (DT_1 that) (NNS_0 giggles))))) (DOT_0 .)))