You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[2-(3-methoxyphenyl)pyrrolidin-1-yl]-(4-methyl-2-propan-2-ylpyrimidin-5-yl)methanone is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H25N3O2
assistant