You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[2-(2-chlorophenyl)ethyl]-2-methyl-3-[(1-methylsulfonylpiperidin-4-yl)methyl]guanidine is the IUPAC name of a molecule. Please give its molecular formula.
user
C17H27ClN4O2S
assistant