['CC(C)CN', 'CCCc1ccc(C=O)cc1', 'CC(C)C', 'CCCc1ccc(C(N)=O)cc1', 'CC(C)CNC=O', 'CCCc1ccccc1', 'CCC', 'CC(C)CNC(=O)c1ccccc1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.