You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
5-bromo-10-chloro-8-[2-(oxan-4-yl)-1-phenylethyl]-3,8,11-triazatricyclo[7.4.0.02,7]trideca-1(9),2(7),3,5,10,12-hexaene The above is the IUPAC name of a molecule. Write its molecular formula.
user
C23H21BrClN3O
assistant