['COCCCN', 'O=CCn1ccc(=O)c2ccccc21', 'CO', 'CCCNC(=O)Cn1ccc(=O)c2ccccc21', 'CCCOC', 'NC(=O)Cn1ccc(=O)c2ccccc21', 'COCCCNC(C)=O', 'O=c1cc[nH]c2ccccc12']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=c1cc[nH]c2ccccc12.