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 10-bromo-6-[2-(4-methoxyphenyl)ethenyl]-3-methylsulfanyl-6,7-dihydro-[1,2,4]triazino[5,6-d][3,1]benzoxazepine is given. What is its corresponding molecular formula?
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C20H17BrN4O2S
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