['CC(C)C=O', 'NCCNC(=O)NCc1ccc(OC(F)(F)F)cc1', 'CC(C)C(=O)NCCN', 'O=CNCc1ccc(OC(F)(F)F)cc1', 'CC(C)C(=O)NCCNC=O', 'NCc1ccc(OC(F)(F)F)cc1', 'OC(F)(F)F', 'CC(C)C(=O)NCCNC(=O)NCc1ccccc1', 'CC(C)C(N)=O', 'CCNC(=O)NCc1ccc(OC(F)(F)F)cc1', 'CCNC(=O)C(C)C', 'NC(=O)NCc1ccc(OC(F)(F)F)cc1', 'Cc1ccc(OC(F)(F)F)cc1', 'CC(C)C(=O)NCCNC(N)=O', 'FC(F)(F)Oc1ccccc1', 'CNC(=O)NCCNC(=O)C(C)C']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.