You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
methyl 2-pyridin-3-yl-5-pyridin-4-yl-[1,2,4]triazolo[1,5-a]pyridine-8-carboxylate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H13N5O2
assistant