You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[5-(2-bromophenyl)-1-methylpyrrol-2-yl]-[(3S)-3-(methylaminomethyl)pyrrolidin-1-yl]methanone is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H22BrN3O
assistant