You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 4-[[2-(4-bromo-3-methylanilino)-2-oxoethyl]amino]-3-nitro-N-propan-2-ylbenzamide by IUPAC nomenclature, provide its molecular formula.
user
C19H21BrN4O4
assistant