You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Under IUPAC nomenclature, a molecule named 6-[(5-bromopyridin-3-yl)methyl]-2-pyridin-4-yl-7,8-dihydro-5H-pyrido[4,3-d]pyrimidine is given. What is its corresponding molecular formula?
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C18H16BrN5
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