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 1-(azepan-1-yl)-2-(3-bromo-8,9-dihydro-6H-pyrido[4,3-b][1,8]naphthyridin-7-yl)ethanone into molecular formula.
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C19H23BrN4O
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