['CC(=O)O', 'Cc1ccc(-c2nnc(S)n2C)cc1C', 'O=C(O)CS', 'Cc1ccc(-c2nncn2C)cc1C', 'Cc1ccccc1C', 'Cn1cnnc1SCC(=O)O']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc(-c2nnc[nH]2)cc1.