You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named N-[1-[2-[[4-(2-amino-2-oxoethoxy)-3-bromophenyl]methylidene]hydrazinyl]-3-methyl-1-oxobutan-2-yl]-4-chlorobenzamide by IUPAC nomenclature, provide its molecular formula.
user
C21H22BrClN4O4
assistant