You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named (2R)-N-[(2R)-1-(cyclohexylamino)-2-methyl-1-oxobutan-2-yl]-5-oxo-N-[[(2S)-oxolan-2-yl]methyl]pyrrolidine-2-carboxamide by IUPAC nomenclature, provide its molecular formula.
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C21H35N3O4
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