You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2S)-2-amino-1-(2-methyl-3-phenylpyrrolidin-1-yl)-4-methylsulfanylbutan-1-one;hydrochloride is the IUPAC name of a molecule. Please give its molecular formula.
user
C16H25ClN2OS
assistant