You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 1-[[(3S)-3-(1,3-benzothiazol-2-yl)piperidin-1-ium-1-yl]methyl]-5-fluoroindole-2,3-dione into its molecular formula.
user
C21H19FN3O2S+
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