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 (2R,3R)-N-(cyclopropylmethyl)-2-methyl-1-(2-methylpropyl)-6-oxo-N-propylpiperidine-3-carboxamide ?
user
C18H32N2O2
assistant