You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[(4R,7S,7aR)-9-acetyloxy-11-iodo-3-methyl-2,4,4a,7,7a,13-hexahydro-1H-4,12-methanobenzofuro[3,2-e]isoquinolin-7-yl] acetate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H22INO5
assistant