['CC', 'N#CCNS(=O)(=O)c1ccc([N+](=O)[O-])cc1Cl', 'CC#N', 'CCNS(=O)(=O)c1ccc([N+](=O)[O-])cc1Cl', 'CCNCC#N', 'O=[N+]([O-])c1ccc([SH](=O)=O)c(Cl)c1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.