You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule (4S)-1-[[(2R,4R,6R)-2-(3-chloro-4-fluorophenyl)-2,6-dimethyl-1-(2,2,2-trifluoroethyl)piperidin-4-yl]methyl]-2-oxoimidazolidine-4-carboxamide .
user
C20H25ClF4N4O2
assistant