You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-tert-butyl-8-pyridin-4-yl-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazine is the IUPAC name of a molecule. Please give its molecular formula.
user
C14H19N5
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