You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named (2S)-1-(2-amino-3-methylbenzimidazol-3-ium-1-yl)-3-(2,4-dichlorophenoxy)propan-2-ol by IUPAC nomenclature, provide its molecular formula.
user
C17H18Cl2N3O2+
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