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 2-[4-[(3,4-dimethoxyphenyl)methyl]piperazine-1,4-diium-1-yl]-N-(3-fluorophenyl)acetamide is given. What is its corresponding molecular formula?
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C21H28FN3O3+2
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