You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named (E)-N-(4-bromophenyl)-2-cyano-3-(3-ethoxy-5-iodo-4-propan-2-yloxyphenyl)prop-2-enamide by IUPAC nomenclature, provide its molecular formula.
user
C21H20BrIN2O3
assistant