You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-ethyl-2-[[6-(2-methoxyethoxy)pyridin-3-yl]methyl]-1-methyl-1-[(2-methyl-1,3-thiazol-4-yl)methyl]guanidine;hydroiodide is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H28IN5O2S
assistant