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 N-(8,8-dimethyl-2-azabicyclo[4.2.0]octan-7-yl)-4-oxo-3H-phthalazine-1-carboxamide into molecular formula.
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C18H22N4O2
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