You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-[[4-[5-(trifluoromethyl)pyridin-1-ium-2-yl]piperazin-1-ium-1-yl]methyl]benzonitrile The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H19F3N4+2
assistant