You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named 5-amino-1-cyclopropyl-7-[(3R,4S)-3-ethyl-4-(methoxycarbonylamino)pyrrolidin-1-yl]-6,8-difluoro-4-oxoquinoline-3-carboxylic acid by IUPAC nomenclature, provide its molecular formula.
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C21H24F2N4O5
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