You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance N-(oxan-4-yl)-3-[3-(trifluoromethoxy)phenyl]-3aH-pyrazolo[1,5-a]pyrimidin-8-ium-5-amine .
user
C18H18F3N4O2+
assistant