You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule (2S,3S)-3-[[5-fluoro-4-(5-fluoro-1H-pyrrolo[2,3-b]pyridin-3-yl)pyrimidin-2-yl]methyl]bicyclo[2.2.2]octane-2-carboxylic acid into molecular formula.
user
C21H20F2N4O2
assistant