Using COc1cc(C(Cl)C(Cl)(Cl)Cl)cc(C(Cl)C(Cl)(Cl)Cl)c1 to produce COc1cc(C(Cl)=C(Cl)Cl)cc(C(Cl)=C(Cl)Cl)c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.