You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 4-[3-[2-nitro-4-(trifluoromethyl)anilino]propanoyl]-N-phenylpiperazine-1-carboxamide by IUPAC nomenclature, provide its molecular formula.
user
C21H22F3N5O4
assistant