You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
7-[(1-ethylbenzimidazol-2-yl)methyl]-2-pyridin-2-yl-3,5,6,8-tetrahydropyrido[3,4-d]pyrimidin-4-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C22H22N6O
assistant