You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-methyl-1-[(1S)-1-(3-methyl-1,2,4-oxadiazol-5-yl)ethyl]-3-[[4-(2-phenylethyl)-1,2,4-triazol-3-yl]methyl]urea The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H23N7O2
assistant