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 5-methyl-4-oxo-N-[[4-(2-phenylethyl)-1,2,4-triazol-3-yl]methyl]-6,7-dihydropyrazolo[1,5-a]pyrazine-2-carboxamide is given. What is its corresponding molecular formula?
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C19H21N7O2
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