You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 3-[5-[(2-azabicyclo[2.2.1]heptan-4-ylmethylamino)methyl]-3-oxo-1H-isoindol-2-yl]piperidine-2,6-dione into its molecular formula.
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C21H26N4O3
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