['C=C(C)C', 'CCNCc1nnc(C2CC2)o1', 'CC', 'C=C(C)CNCc1nnc(C2CC2)o1', 'C=C(C)CNCC', 'Cc1nnc(C2CC2)o1', 'C=C(C)CN(C)CC', 'c1nnc(C2CC2)o1', 'C1CC1', 'C=C(C)CN(CC)Cc1nnco1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1nnc(C2CC2)o1.