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What is the molecular formula of the molecule methyl (1R,3R,3aR,6aS)-1-(4-chlorophenyl)-5-methyl-4,6-dioxo-3-propan-2-yl-1,2,3a,6a-tetrahydropyrrolo[3,4-c]pyrrol-2-ium-3-carboxylate ?
user
C18H22ClN2O4+
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