['NC=O', 'CC(C)[C@@H](N)C(=O)Nc1cccc(C#N)c1', 'N#Cc1cccc(N)c1', 'CC(C)[C@H](C=O)NC(N)=O', 'NC(N)=O', 'CC(C)CC(=O)Nc1cccc(C#N)c1', 'N#Cc1ccccc1', 'CC(C)[C@@H](NC(N)=O)C(N)=O']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.