You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named 2-amino-5-[carbamimidoyl-[2-[4,5-dibromo-3-[(3,5-dichlorophenyl)methylamino]-2-sulfanylphenyl]sulfonylacetyl]amino]pentanoic acid by IUPAC nomenclature, provide its molecular formula.
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C21H23Br2Cl2N5O5S2
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