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 1,3-dihydroxypropan-2-yl 4-[[(Z)-hex-3-enoyl]amino]-2-[(5-methyl-4-oxidopyrazin-4-ium-2-carbonyl)amino]butanoate into molecular formula.
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C19H28N4O7
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