You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule N-(2-chlorophenyl)-4-[(5E)-5-[(2-chlorophenyl)methylidene]-4-oxo-2-sulfanylidene-1,3-thiazolidin-3-yl]butanamide into molecular formula.
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C20H16Cl2N2O2S2
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