You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name (4Z)-4-[2,3-dihydro-1-benzofuran-5-yl(hydroxy)methylidene]-5-(3-methylthiophen-2-yl)-1-propylpyrrolidine-2,3-dione into its molecular formula.
user
C21H21NO4S
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