['CCO', 'Nc1nc(SCCCO)ncc1C=O', 'CC', 'Nc1nc(SCCCO)ncc1C(=O)O', 'CCCO', 'CCOC(=O)c1cnc(S)nc1N', 'CCOC=O', 'Nc1ccnc(SCCCO)n1', 'OCCCS', 'CCOC(=O)c1cncnc1N']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1cncnc1.