['Cn1cc(C#N)c(=O)n(C)c1=O', 'Cn1c(N2CCCNCC2)c(C#N)c(=O)n(C)c1=O']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=c1cc(N2CCCN(c3cc(=O)[nH]c(=O)[nH]3)CC2)[nH]c(=O)[nH]1.