You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-methyl-1-piperidin-4-yl-3-[3-[3-(trifluoromethyl)cyclohexyl]-1,2-dihydropyrazin-6-yl]urea The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H28F3N5O
assistant