You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-methyl-1-[(5-methyl-1,2-oxazol-3-yl)methyl]-3-(4-methyl-2-phenylmethoxyphenyl)urea The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H23N3O3
assistant