You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 5-[(3-chloro-5-methoxy-4-prop-2-enoxyphenyl)methylidene]-3-[(4-chlorophenyl)methyl]-1,3-thiazolidine-2,4-dione into its molecular formula.
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C21H17Cl2NO4S
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