You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-[(2,5-difluorophenyl)methyl]-1-(2-pyridin-4-ylpyridine-3-carbonyl)piperidine-4-carbonitrile is the IUPAC name of a molecule. Please give its molecular formula.
user
C24H20F2N4O
assistant