You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2Z)-2-[(6-bromo-4H-1,3-benzodioxin-8-yl)methylidene]-6-ethoxy-4-methyl-1-benzofuran-3-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H17BrO5
assistant