You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Convert the IUPAC name of a molecule (1R,2R,6R,7R)-4-[4-oxo-4-(4-pyrimidin-2-ylpiperazin-1-yl)butyl]-4-azatricyclo[5.2.1.02,6]dec-8-ene-3,5-dione into molecular formula.
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C21H25N5O3
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