You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 2-[2-(3-butoxyphenyl)ethyl-[[(3R)-oxolan-3-yl]methyl]amino]-N,N-dimethylacetamide by IUPAC nomenclature, provide its molecular formula.
user
C21H34N2O3
assistant