You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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N-[3-(5-bromo-1H-pyrrolo[2,3-b]pyridine-3-carbonyl)-2,4-difluorophenyl]-1-phenylmethanesulfonamide is the IUPAC name of a molecule. Please give its molecular formula.
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C21H14BrF2N3O3S
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