['CC', 'N#CCNS(=O)(=O)c1ccc([N+](=O)[O-])cc1', 'CC#N', 'CCNS(=O)(=O)c1ccc([N+](=O)[O-])cc1', 'CCNCC#N', 'O=[N+]([O-])c1ccc([SH](=O)=O)cc1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.