You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
methyl 2-oxo-2-[4-[4-[4-(trifluoromethoxy)phenyl]piperazin-1-yl]anilino]acetate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H20F3N3O4
assistant