You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 1-[[2-[(dimethylamino)methyl]phenyl]methyl]-3-[2-(2-methoxyphenyl)ethyl]-2-methylguanidine;hydroiodide by IUPAC nomenclature, provide its molecular formula.
user
C21H31IN4O
assistant