[{"from": "human", "value": "Given SMILES, write its weight-averaged molecular weight at normal measurement conditions.. ->  CC1=CC([Si]2(CCCCCCCC)CCCCCCCC)=C(S1)C(C2=C3)=CC4=C3C5=C([Si]4(CCCCCCCC)CCCCCCCC)C=C(C6=CC=C(C)C7=NSN=C76)S5\n"}, {"from": "gpt", "value": " 909\n"}]