You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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1-[(3S,4R)-3-amino-4-phenylpyrrolidin-1-yl]-3-(3-fluoro-4-methoxyphenyl)propan-1-one is the IUPAC name of a molecule. Please give its molecular formula.
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C20H23FN2O2
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