You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule 2-[(2,4-dimethoxyphenyl)methyl]-1-ethyl-3-[(1-methylbenzimidazol-2-yl)methyl]guanidine;hydroiodide into molecular formula.
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C21H28IN5O2
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