You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named 3-[(1S,4S)-5-(bicyclo[2.2.1]heptane-1-carbonyl)-2,5-diazabicyclo[2.2.1]heptan-2-yl]-1-methylpyrrolidin-2-one by IUPAC nomenclature, provide its molecular formula.
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C18H27N3O2
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