You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 2,7,9-trimethyl-5-(3,4,5-trimethoxyphenyl)-5,6-dihydropyrazolo[1,5-c]quinazoline by IUPAC nomenclature, provide its molecular formula.
user
C22H25N3O3
assistant