Using CCS, FC(F)(F)c1cc(Cl)c(-n2ncc(CBr)n2)c(Cl)c1 to produce CCSCc1cnn(-c2c(Cl)cc(C(F)(F)F)cc2Cl)n1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.