You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named 2-[(5E)-5-[[2-bromo-5-ethoxy-4-[(3-fluorophenyl)methoxy]phenyl]methylidene]-2,4-dioxo-1,3-thiazolidin-3-yl]acetic acid by IUPAC nomenclature, provide its molecular formula.
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C21H17BrFNO6S
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