['CO', 'CCN(c1ccccc1)S(=O)(=O)CCCC=O', 'CC', 'COC(=O)CCCS(=O)(=O)Nc1ccccc1', 'CCNc1ccccc1', 'COC(=O)CCC[SH](=O)=O', 'c1ccccc1', 'CCNS(=O)(=O)CCCC(=O)OC']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.