You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named 1-[(4-chloro-2-fluorophenyl)methyl]-5-(4-pyrrolidin-1-ylsulfonylphenyl)pyridin-2-one by IUPAC nomenclature, provide its molecular formula.
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C22H20ClFN2O3S
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