You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[2-(3,5-dimethyl-1,2-oxazol-4-yl)ethyl]-2-methyl-3-(9-methyl-9-azabicyclo[3.3.1]nonan-3-yl)guanidine is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H31N5O
assistant