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 2-(4-methyl-1-oxophthalazin-2-yl)-N-(2,2,6,6-tetramethylpiperidin-4-yl)acetamide is given. What is its corresponding molecular formula?
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C20H28N4O2
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