You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-ethyl-2-[(4-fluorophenyl)methyl]-3-[2-(4-sulfamoylphenyl)ethyl]guanidine;hydroiodide is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H24FIN4O2S
assistant