You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[4-[4-[2-(4-methoxyphenyl)ethyl]piperidin-1-yl]-4-oxobutyl]-2,2-dimethylpropanamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C23H36N2O3
assistant