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-(2-ethoxyethyl)-5-oxo-[1,3,4]thiadiazolo[3,2-a]pyrimidin-7-yl]methyl 2-(1,3-dioxoisoindol-2-yl)acetate by IUPAC nomenclature, provide its molecular formula.
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C20H18N4O6S
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