You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-[[N'-methyl-N-[(3,4,5-trimethoxyphenyl)methyl]carbamimidoyl]amino]-N-propylpropanamide;hydroiodide is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H31IN4O4
assistant