You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[1-(2-methoxypyrimidin-4-yl)piperidin-4-yl]-1-[4-(3-methylphenyl)piperazin-1-yl]ethanone is the IUPAC name of a molecule. Please give its molecular formula.
user
C23H31N5O2
assistant