You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Under IUPAC nomenclature, a molecule named ethyl 2-[4-[(E)-[(5-chloro-1-benzofuran-2-carbonyl)hydrazinylidene]methyl]-2-iodo-6-methoxyphenoxy]acetate is given. What is its corresponding molecular formula?
user
C21H18ClIN2O6
assistant