You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-methyl-1-[1-(1-phenylethyl)pyrrolidin-3-yl]-3-(pyridin-2-ylmethyl)guanidine;hydroiodide is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H28IN5
assistant