['CC', 'Cc1oncc1-c1noc(C2CC2)n1', 'C1CC1', 'CCc1noc(C)c1-c1ncon1', 'c1noc(C2CC2)n1', 'CCc1cc(C)on1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1nocc1-c1noc(C2CC2)n1.