You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(7R)-7-(3-hydroxyphenyl)-N-(2-methoxyphenyl)-5-methyl-4,7-dihydro-[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
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C20H19N5O3
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