['Cn1nc2c(c1N)CCC2', 'O=C/C=C/c1c(F)cccc1F', 'Cn1cc2c(n1)CCC2', 'NC(=O)/C=C/c1c(F)cccc1F', 'Cc1c(F)cccc1F', 'CC(=O)Nc1c2c(nn1C)CCC2']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is O=C(/C=C/c1ccccc1)Nc1[nH]nc2c1CCC2.