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 [(4aS,5R)-8-nitro-3-pyridin-2-yl-1,2,4,4a,5,6-hexahydropyrazino[1,2-a]quinolin-5-yl]-(3,4-dihydro-1H-isoquinolin-2-yl)methanone into molecular formula.
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C27H27N5O3
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