['CC', 'N#CCNS(=O)(=O)c1ccccc1[N+](=O)[O-]', 'CC#N', 'CCNS(=O)(=O)c1ccccc1[N+](=O)[O-]', 'CCNCC#N', 'O=[N+]([O-])c1ccccc1[SH](=O)=O']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.