You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule ethyl 2-(4-fluorophenyl)-5-methyl-7-pyridin-3-yl-4,7-dihydro-[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylate .
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C20H18FN5O2
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