['NC1CCCCC1', 'N#Cc1cc([N+](=O)[O-])cc([N+](=O)[O-])c1', 'C1CCCCC1', 'N#Cc1cc([N+](=O)[O-])c(N)c([N+](=O)[O-])c1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc(NC2CCCCC2)cc1.