Using CCOC(=O)c1nc(-c2ccc(F)c(Cl)c2)cs1, O=C1CCC(=O)N1Br to produce CCOC(=O)c1nc(-c2ccc(F)c(Cl)c2)c(Br)s1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.