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What is the molecular formula of the compound with this IUPAC name 3-[4-[(3aR,9bR)-9-methoxy-3,3a,4,9b-tetrahydro-1H-chromeno[3,4-c]pyrrol-2-yl]butyl]-2-oxo-1,3-dihydropyrimido[5,4-h]cinnolin-2-ium-4-one ?
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C26H28N5O4+
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