['CC(C)CCC=O', 'CCN(CC)CCn1cc(N)cn1', 'CC', 'CCNCCn1cc(NC(=O)CCC(C)C)cn1', 'CCNCC', 'CCn1cc(NC(=O)CCC(C)C)cn1', 'CC(C)CCC(N)=O', 'CCN(CC)CCn1cccn1', 'CCN(CC)CC', 'CC(C)CCC(=O)Nc1cn[nH]c1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1cn[nH]c1.