Using CCOC(=O)C(OCC)c1c(F)cc(O)cc1F, O=S(=O)(OS(=O)(=O)C(F)(F)F)C(F)(F)F to produce CCOC(=O)C(OCC)c1c(F)cc(OS(=O)(=O)C(F)(F)F)cc1F, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.