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 3-bromo-5-thiophen-2-yl-1,2-didehydro-3,3a-dihydropyrazolo[1,5-a]pyrimidin-1-ium into molecular formula.
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C10H7BrN3S+
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