You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Convert the IUPAC name of a molecule (5S)-5-(4-chlorophenyl)-4-[(4-chlorophenyl)-hydroxymethylidene]-1-[(3R)-1,1-dioxothiolan-3-yl]pyrrolidine-2,3-dione into molecular formula.
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C21H17Cl2NO5S
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