You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-(4-methoxyphenyl)-1-[4-[2-(2-methylpiperidin-1-yl)-2-oxoethyl]piperazin-1-yl]propan-1-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C22H33N3O3
assistant