You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named 5-[3-[(2S,3S)-3-hydroxybutan-2-yl]oxy-5-[[(Z)-3-(methylamino)prop-2-enimidoyl]carbamoyl]phenoxy]pyrazine-2-carboxylic acid by IUPAC nomenclature, provide its molecular formula.
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C20H23N5O6
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