You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Under IUPAC nomenclature, a molecule named 3-phenyl-1-[(1S,5R)-3-(pyrazine-2-carbonyl)-3,6-diazabicyclo[3.2.2]nonan-6-yl]propan-1-one is given. What is its corresponding molecular formula?
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C21H24N4O2
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