['CCO', 'COc1c(Cl)cc(C=O)cc1Br', 'CC', 'COc1c(Cl)cc(C(=O)O)cc1Br', 'CO', 'CCOC(=O)c1cc(Cl)cc(Br)c1', 'CCOC=O', 'COc1c(Cl)cccc1Br']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.