You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-(furan-2-yl)-6-[(2-methoxypyridin-3-yl)methyl]-3,5,7,8-tetrahydropyrido[4,3-d]pyrimidin-4-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H18N4O3
assistant