['N#CCCN', 'O=CCN1CCCc2cccc(OC(F)F)c21', 'OC(F)F', 'N#CCCNC(=O)CN1CCCc2ccccc21', 'CCC#N', 'NC(=O)CN1CCCc2cccc(OC(F)F)c21', 'CC(=O)NCCC#N', 'FC(F)Oc1cccc2c1NCCC2']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc2c(c1)CCCN2.