['Cc1nnn(C)n1', 'CC(C)(C)C1NC(=O)NC1=O', 'CC(C)C', 'Cn1nnc(CN2C(=O)CNC2=O)n1', 'Cn1ncnn1', 'CN1C(=O)NC(C(C)(C)C)C1=O']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=C1CNC(=O)N1Cc1nn[nH]n1.