You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named (1R)-1-(4-bromophenyl)-7-chloro-2-[5-[(4-methylphenyl)methylsulfanyl]-1,3,4-thiadiazol-2-yl]-1H-chromeno[2,3-c]pyrrole-3,9-dione by IUPAC nomenclature, provide its molecular formula.
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C27H17BrClN3O3S2
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