You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named 3-[(2R,5S,8R,11S,14S)-14-(carboxymethyl)-11-(1H-indol-3-ylmethyl)-8-(2-methylpropyl)-3,6,9,12,15-pentaoxo-5-propan-2-yl-1,4,7,10,13-pentazacyclopentadec-2-yl]propanoic acid by IUPAC nomenclature, provide its molecular formula.
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C31H42N6O9
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