[{"from": "human", "value": "Given SMILES, write its number-averaged molecular weight at room temperature and atmospheric pressure. ->  CC(S1)=CC=C1C2=CC=C(C(S3)=CC=C3C(S4)=CC(C4=C5OCCCCCCCC)=C(OCCCCCCCC)C6=C5C=C(C)S6)C7=C2N=C(C8=CC=C(CCCCCC)S8)C(C9=CC=C(CCCCCC)S9)=N7\n"}, {"from": "gpt", "value": " 4.99\n"}]