You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 5-[4-[2-(difluoromethoxy)benzoyl]piperazine-1-carbonyl]-2-methylisoindole-1,3-dione by IUPAC nomenclature, provide its molecular formula.
user
C22H19F2N3O5
assistant