You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name (2S)-1-[2-amino-3-[2-(diethylamino)ethyl]benzimidazol-1-ium-1-yl]-3-phenoxypropan-2-ol into its molecular formula.
user
C22H31N4O2+
assistant