You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-(methylamino)-2-(1-methylpyrazol-4-yl)-N-[1-[2-(trifluoromethyl)phenyl]ethyl]acetamide;hydrochloride is the IUPAC name of a molecule. Please give its molecular formula.
user
C16H20ClF3N4O
assistant