You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named 1-[3-bromo-5-(1,2,3,6-tetrahydropyridin-4-yl)-2H-pyridin-1-yl]ethanone by IUPAC nomenclature, provide its molecular formula.
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C12H15BrN2O
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