You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[(5-ethyl-1,3-thiazol-2-yl)methyl]-3-[(2-fluorophenyl)methyl]-2-methylguanidine;hydroiodide is the IUPAC name of a molecule. Please give its molecular formula.
user
C15H20FIN4S
assistant