['Cc1ccccc1', 'CNS(=O)(=O)CCC(=O)NN', 'CNCc1ccccc1', 'NNC(=O)CC[SH](=O)=O', 'c1ccccc1', 'CN(C)S(=O)(=O)CCC(=O)NN']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.