You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-(4-imidazo[1,2-a]pyridin-2-ylphenyl)-N-(1,4,5,6-tetrahydropyrimidin-2-yl)methanimine The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H17N5
assistant