You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 2-[[3-[(2R)-2-[[(2R)-2-(3-chlorophenyl)-2-hydroxyethyl]amino]propyl]-2,3-dihydro-1H-indol-7-yl]oxy]acetic acid into its molecular formula.
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C21H25ClN2O4
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