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For the molecule named 2-[[(4aS,8aR)-1-(3-methylbutyl)-2-oxo-4,4a,5,7,8,8a-hexahydro-3H-1,6-naphthyridin-6-yl]methyl]-8-methylpyrido[1,2-a]pyrimidin-4-one by IUPAC nomenclature, provide its molecular formula.
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C23H32N4O2
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