[{"from": "human", "value": "Given SMILES, write its weight-averaged molecular weight at normal measurement conditions.. ->  CC1=C(CCCCCC)C=C(C(S2)=NC3=C2N=C(S3)C4=CC(CCCCCC)=C(C5=CC6=C(C(OCCCCCCCC)=C(OCCCCCCCC)C7=C6C=C(C)S7)S5)S4)S1\n"}, {"from": "gpt", "value": " 17.2\n"}]