You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 3-[4-oxo-2-[(Z)-[2-oxo-5-(1-phenylethylamino)-1H-indol-3-ylidene]methyl]-1,5,6,7-tetrahydroindol-3-yl]propanoic acid into its molecular formula.
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C28H27N3O4
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