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 [(2R)-2-(5-methyl-1,2,4-oxadiazol-3-yl)pyrrolidin-1-yl]-(1-propan-2-ylbenzimidazol-5-yl)methanone into its molecular formula.
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C18H21N5O2
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