You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[(1R,2R,3S)-2,3-dimethylcyclohexyl]-2-(4-pyridin-2-ylpiperazin-1-yl)acetamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C19H30N4O
assistant