You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[[4-(2-chlorophenyl)oxan-4-yl]methyl]-3-ethyl-2-(2-methoxy-2-methylpropyl)guanidine;hydroiodide is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H33ClIN3O2
assistant