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Under IUPAC nomenclature, a molecule named 4-[5-(1,3-benzodioxol-5-yl)-1,2,4-oxadiazol-3-yl]-1-[(3-chloro-4-fluorophenyl)methyl]pyrrolidin-2-one is given. What is its corresponding molecular formula?
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C20H15ClFN3O4
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