Using BrC(Br)(Br)Br, OCC1Cc2ccccc2C(c2ccc(Cl)c(Cl)c2)C1 to produce Clc1ccc(C2CC(CBr)Cc3ccccc32)cc1Cl, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.