['NCCNCCO', 'Cc1cccc(C)c1', 'CCNCCO', 'Cc1cccc(CN)c1', 'NCCO', 'CCNCc1cccc(C)c1', 'CCO', 'Cc1cccc(CNCCN)c1', 'Cc1ccccc1', 'CNCCNCCO']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.