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-(2-cyclopropyl-4,7a-dihydro-1H-pyrrolo[2,3-b]pyrazin-7-yl)-2-oxo-N-(2-phenylethyl)acetamide is given. What is its corresponding molecular formula?
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C19H20N4O2
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