Using O=[N+]([O-])OCC(CBr)(CO[N+](=O)[O-])CO[N+](=O)[O-], CO to produce COCC(CO[N+](=O)[O-])(CO[N+](=O)[O-])CO[N+](=O)[O-], please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.