Using CCCc1cc([Sn](C)(C)C)nc(C#N)n1, FC(F)(F)c1cc(Br)cc(C(F)(F)F)c1 to produce CCCc1cc(-c2cc(C(F)(F)F)cc(C(F)(F)F)c2)nc(C#N)n1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.