Using [NH4+], Nc1c([N+](=O)[O-])c(N)c([N+](=O)[O-])c(O)c1[N+](=O)[O-] to produce Nc1c([N+](=O)[O-])c(N)c([N+](=O)[O-])c(N)c1[N+](=O)[O-], please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.