['CC(C)c1ncon1', 'CC1(C)CNCC(C(F)(F)F)O1', 'FC(F)F', 'CC(C)c1noc(N2CCOC(C)(C)C2)n1', 'CCC', 'CC1(C)CN(c2ncno2)CC(C(F)(F)F)O1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1noc(N2CCOCC2)n1.