['CO', 'O=CCN(C(=O)CCl)c1ccc(F)cc1', 'O=CCCl', 'COC(=O)CNc1ccc(F)cc1', 'COC(C)=O', 'O=C(CCl)Nc1ccc(F)cc1', 'Fc1ccccc1', 'COC(=O)CNC(=O)CCl']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.