Using N[C@@H](CCC(=O)N[C@@H](CS)C(=O)NCC(=O)O)C(=O)O, Fc1ccccc1CCl to produce N[C@@H](CCC(=O)N[C@@H](CSCc1ccccc1F)C(=O)NCC(=O)O)C(=O)O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.