['CC(C)(C)NCC=O', 'Nc1nc(C2CC2)cs1', 'CC(C)C', 'NCC(=O)Nc1nc(C2CC2)cs1', 'CC(C)(C)N', 'CC(=O)Nc1nc(C2CC2)cs1', 'c1nc(C2CC2)cs1', 'CC(C)(C)NCC(N)=O', 'C1CC1', 'CC(C)(C)NCC(=O)Nc1nccs1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1nc(C2CC2)cs1.