You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 1-[1-[(4-fluorophenyl)methyl]piperidin-4-yl]-4-methylpiperazin-4-ium;2-hydroxy-2-oxoacetate into its molecular formula.
user
C19H28FN3O4
assistant