['CCNCC', 'O=CCC1(C(=O)O)CCCC1', 'CC', 'CCNC(=O)CC1(C(=O)O)CCCC1', 'O=CO', 'CCN(CC)C(=O)CC1CCCC1', 'CCN(CC)C(C)=O', 'O=C(O)C1CCCC1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is C1CCCC1.