[{"from": "human", "value": "Given SMILES, write its weight-averaged molecular weight at normal measurement conditions.. ->  CC1=CC(CC(CCCCCC)CCCC)=C(C2=NC(SC(C3=C(CC(CCCCCC)CCCC)C=C(C4=CC(CC(CCCCCCCC)CCCCCC)=C(C5=NC(SC(C6=C(CC(CCCCCCCC)CCCCCC)C=C(C)S6)=N7)=C7S5)S4)S3)=N8)=C8S2)S1\n"}, {"from": "gpt", "value": " 3.1\n"}]