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 2-methyl-1-[4-(4-methylpiperidin-1-yl)butyl]-3-[2-(4-methylsulfonylphenyl)ethyl]guanidine;hydroiodide .
user
C21H37IN4O2S
assistant