You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-(3-methylphenyl)-1-[(3Z)-3-(oxolan-2-yloxyimino)propyl]pyrido[1,2-a]pyrimidin-1-ium-4-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C22H24N3O3+
assistant