You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name (2R)-2-(3,4,4a,5,6,7,8,8a-octahydro-1H-isoquinoline-2-carbonylamino)-3-methylbutanoic acid into its molecular formula.
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C15H26N2O3
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