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-[(11aS)-1,4-dioxo-3,6,11,11a-tetrahydropyrazino[1,2-b]isoquinolin-2-yl]-2-(4-methylphenyl)-N-[2-(4-methylphenyl)ethyl]acetamide is given. What is its corresponding molecular formula?
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C30H31N3O3
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