You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[(3-methyl-2-methylsulfanylimidazol-4-yl)methyl]-3-[4-(oxolan-2-ylmethoxy)phenyl]urea is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H24N4O3S
assistant