You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 3-(2-methoxyphenyl)-1,4-dimethyl-8-[(7-methyl-8,9-dihydro-7H-benzo[7]annulen-3-yl)methyl]imidazo[1,2-a]pyrazine-1,4-diium into its molecular formula.
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C28H31N3O+2
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