You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 1-[6-[4-(2-fluorophenyl)piperazin-1-yl]-5-nitropyrimidin-4-yl]piperidine-4-carboxylic acid into its molecular formula.
user
C20H23FN6O4
assistant