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 1-[(2,5-difluorophenyl)methyl]-3-[2-(5-fluoro-1H-indol-3-yl)ethyl]-2-methylguanidine is given. What is its corresponding molecular formula?
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C19H19F3N4
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