['C[C@@H](C=O)NC(N)=O', 'CC1CNCCC1(F)F', 'NC=O', 'CC1CN(C(=O)[C@H](C)N)CCC1(F)F', 'NC(N)=O', 'CCC(=O)N1CCC(F)(F)C(C)C1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is C1CCNCC1.