You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the compound with this IUPAC name 1-(4-ethylpiperazin-1-yl)-2-[1-[(2S,4S)-2-methylpiperidine-4-carbonyl]piperidin-4-yl]ethanone ?
user
C20H36N4O2
assistant