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 N-[3-[6-amino-8-[(6-bromo-2,3-dihydro-1,4-benzodioxin-7-yl)sulfanyl]purin-9-yl]-1-cyclopropylpropyl]acetamide is given. What is its corresponding molecular formula?
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C21H23BrN6O3S
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