You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[3-(3,4-difluorobenzoyl)-1,1-dimethyl-2,6-dihydroazepino[4,5-b]indol-5-yl]ethanone The above is the IUPAC name of a molecule. Write its molecular formula.
user
C23H20F2N2O2
assistant