You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Under IUPAC nomenclature, a molecule named (4-benzylpiperazin-4-ium-1-yl)-[(3S)-6-chloro-3,4-dihydro-2H-chromen-3-yl]methanone is given. What is its corresponding molecular formula?
user
C21H24ClN2O2+
assistant