You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 3-[2-(1-ethylpiperidin-4-yl)ethyl]-1-[(2-methoxyphenyl)methyl]-1,2-dimethylguanidine by IUPAC nomenclature, provide its molecular formula.
user
C20H34N4O
assistant