['CC(C)O', 'CCCNc1nn2cc(C)nc2s1', 'CCC', 'Cc1cn2nc(NCCCO)sc2n1', 'CCCOC(C)C', 'Cc1cn2nc(N)sc2n1', 'CC(C)OCCCN', 'Cc1cn2ncsc2n1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1cn2ncsc2n1.