You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-[[5-[[4-(3-chlorophenyl)-2-(ethylsulfonylmethyl)-5-oxopiperazin-1-yl]methyl]imidazol-1-yl]methyl]benzonitrile;chloride is the IUPAC name of a molecule. Please give its molecular formula.
user
C25H26Cl2N5O3S-
assistant