['CC(C)(C)NCC=O', 'NC(=O)Cc1ccc(N)cc1', 'CC(C)C', 'NCC(=O)Nc1ccc(CC(N)=O)cc1', 'CC(C)(C)N', 'CC(=O)Nc1ccc(CC(N)=O)cc1', 'CC(C)(C)NCC(N)=O', 'NC(=O)Cc1ccccc1', 'CC(N)=O', 'CC(C)(C)NCC(=O)Nc1ccccc1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.