You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3R)-1-benzyl-3-[4-[3-(trifluoromethyl)phenyl]piperazin-1-yl]pyrrolidine-2,5-dione The above is the IUPAC name of a molecule. Write its molecular formula.
user
C22H22F3N3O2
assistant