You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[4-[(3-bromophenyl)methyl]piperazin-4-ium-1-yl]-[(2R)-oxolan-2-yl]methanone The above is the IUPAC name of a molecule. Write its molecular formula.
user
C16H22BrN2O2+
assistant