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Under IUPAC nomenclature, a molecule named 4-[1-(2-ethoxyethyl)-3-formyl-7-(pyrimidin-4-ylamino)pyrazolo[4,3-d]pyrimidin-5-yl]piperazine-1-carboxylic acid is given. What is its corresponding molecular formula?
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C19H23N9O4
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