You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[(2S)-2-[1-[(2-bromophenyl)methyl]piperidin-4-yl]azepan-1-yl]-cyclopropylmethanone The above is the IUPAC name of a molecule. Write its molecular formula.
user
C22H31BrN2O
assistant