You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Convert the IUPAC name of a molecule 3-nitro-2-[[1-(pyridine-3-carbonyl)-2,3-dihydroindol-5-yl]amino]pyrido[1,2-a]pyrimidin-4-one into molecular formula.
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C22H16N6O4
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