You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[2-(3,4-dihydro-2H-quinolin-1-yl)-2-oxoethyl]-3-[[3-(2-hydroxyethyl)oxolan-3-yl]methyl]-2-methylguanidine;hydroiodide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H31IN4O3
assistant