['CC(C)CN', 'CON(C)S(=O)(=O)c1cccc(C=O)c1', 'CC(C)C', 'CON(C)S(=O)(=O)c1cccc(C(N)=O)c1', 'CC(C)CNC=O', 'CON(C)S(=O)(=O)c1ccccc1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.