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What is the molecular formula of the compound with this IUPAC name (15R,19R)-17-(4-methoxy-2-nitrophenyl)-8-methyl-16,18-dioxo-17-azapentacyclo[6.6.5.02,7.09,14.015,19]nonadeca-2,4,6,9,11,13-hexaene-1-carbaldehyde ?
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C27H20N2O6
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