You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Convert the IUPAC name of a molecule 2-amino-5-[4-[4-[[amino-[(3,5-diamino-6-chloropyrazine-2-carbonyl)amino]methylidene]amino]butyl]phenyl]pentanoic acid into molecular formula.
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C21H29ClN8O3
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