You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Under IUPAC nomenclature, a molecule named (3R)-1-[2-(3-fluoro-4-pyrazin-2-ylphenyl)phenyl]sulfonylpyrrolidin-3-amine is given. What is its corresponding molecular formula?
user
C20H19FN4O2S
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