You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 5-[2-(4-methoxyphenyl)pyrimidin-4-yl]-2-methyl-3,4,6,7-tetrahydroimidazo[4,5-c]pyridine by IUPAC nomenclature, provide its molecular formula.
user
C18H19N5O
assistant