['CC(=O)O', 'FC(F)(F)c1ccc2nc(S)[nH]c2c1', 'FC(F)F', 'O=C(O)CSc1nc2ccccc2[nH]1', 'O=C(O)CS', 'FC(F)(F)c1ccc2nc[nH]c2c1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc2[nH]cnc2c1.