You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[(2-ethyl-1,3-thiazol-4-yl)methyl]-3-[2-(2-methoxy-5-methylphenyl)ethyl]-2-methylguanidine is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H26N4OS
assistant