Using CCCC[Sn](Cl)(CCCC)CCCC, FC(F)(F)c1ccn2c(Br)cnc2n1 to produce CCCC[Sn](CCCC)(CCCC)c1cnc2nc(C(F)(F)F)ccn12, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.