You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named 2-[(3R,3aR,6aR)-5-[(3,5-dimethyl-1,2-oxazol-4-yl)methyl]-2,3,3a,4,6,6a-hexahydrofuro[2,3-c]pyrrol-3-yl]-1-pyrrolidin-1-ylethanone by IUPAC nomenclature, provide its molecular formula.
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C18H27N3O3
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