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What is the molecular formula of the molecule 3-[(2E)-2-[(E)-4-(4,6-dioxo-2-sulfanylidene-1,3-diazinan-5-ylidene)but-2-enylidene]-1,3-benzoselenazol-3-yl]propane-1-sulfonic acid ?
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C18H17N3O5S2Se
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