Using NCc1ccc(C(=O)NCCC(=O)O)cc1, CCCC1CCC(=O)CC1 to produce CCCC1CCC(NCc2ccc(C(=O)NCCC(=O)O)cc2)CC1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.