You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-[[3-[(3,4-dimethoxyphenyl)methyl]pyrrolidin-1-yl]methyl]-2-ethyl-5-methyl-1H-imidazole The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H29N3O2
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