Using O=C([O-])c1cc(C(=O)[O-])c2cc(C(=O)[O-])cc(C(=O)[O-])c2c1 to produce O=C(O)c1cc(C(=O)O)c2cc(C(=O)O)cc(C(=O)O)c2c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.