You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named 4-(dimethylamino)-N-[2-(dimethylamino)-5-[[4-(1-methylindol-3-yl)pyrazolo[1,5-a][1,3,5]triazin-2-yl]amino]phenyl]but-2-enamide by IUPAC nomenclature, provide its molecular formula.
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C28H31N9O
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