You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule (1R,2S)-2-(3-fluorophenyl)-N-[3-methoxy-4-(2-oxopyrrolidin-1-yl)phenyl]cyclopropane-1-carboxamide into molecular formula.
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C21H21FN2O3
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