Using CCCCCc1ccc(-c2ccc(C=O)cc2)cc1, BrC(Br)(Br)Br to produce CCCCCc1ccc(-c2ccc(C=C(Br)Br)cc2)cc1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.