['Cc1ccccc1', 'Cc1ccc(C2=NCC(=O)N2CCC(=O)O)cc1', 'CCC(=O)O', 'Cc1ccc(C2=N/C(=C\\c3ccccc3)C(=O)N2)cc1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=C1NC(c2ccccc2)=N/C1=C\c1ccccc1.