['Fc1ccccc1', 'O=CNNC(=O)/C=C/c1cc2ccccc2o1', 'Cc1cc2ccccc2o1', 'CC(=O)NNC(=O)c1ccccc1F']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=C(/C=C/c1cc2ccccc2o1)NNC(=O)c1ccccc1.