You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named [2-(2-fluoro-4-methylsulfonylphenyl)-5-piperidin-4-ylbenzimidazol-1-yl] 2,2,2-trifluoroacetate by IUPAC nomenclature, provide its molecular formula.
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C21H19F4N3O4S
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