You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Under IUPAC nomenclature, a molecule named (E)-4-[2-(4-benzhydrylpiperazin-4-ium-1-carbonyl)anilino]-4-oxobut-2-enoate is given. What is its corresponding molecular formula?
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C28H27N3O4
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