You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[(2S,6R)-2,6-dimethylpiperazin-1-yl]-(3-phenyl-3,4-dihydropyrazol-2-yl)methanone The above is the IUPAC name of a molecule. Write its molecular formula.
user
C16H22N4O
assistant