['CN(C)C(=O)CO', 'O=Cc1ccc2c3c(cccc13)CC2', 'CNC', 'O=CCOC(=O)c1ccc2c3c(cccc13)CC2', 'CC(=O)N(C)C', 'O=C(O)c1ccc2c3c(cccc13)CC2', 'CN(C)C(=O)COC=O', 'c1cc2c3c(cccc3c1)CC2']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1cc2c3c(cccc3c1)CC2.