You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[1-(3,5-dimethyl-1,2-oxazol-4-yl)ethyl]-3-(4-hydroxy-3-methylbutan-2-yl)urea is the IUPAC name of a molecule. Please give its molecular formula.
user
C13H23N3O3
assistant