You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named (6,7-dimethoxy-4-oxo-3H-quinazolin-2-yl)methyl-ethyl-[(4-propan-2-ylphenyl)methyl]azanium by IUPAC nomenclature, provide its molecular formula.
user
C23H30N3O3+
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