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 (7R)-N-(4-ethoxyphenyl)-5-oxo-2-phenyl-6,7-dihydro-4H-[1,2,4]triazolo[1,5-a]pyrimidine-7-carboxamide is given. What is its corresponding molecular formula?
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C20H19N5O3
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