You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Translate the chemical IUPAC name [(4R,4aS,7aS)-6-(furan-2-ylmethyl)-4-methoxy-3,4,4a,5,7,7a-hexahydro-2H-pyrrolo[3,4-b]pyridin-1-yl]-(4-fluorophenyl)methanone into its molecular formula.
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C20H23FN2O3
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