You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 2-[(1S)-3,4-dihydro-1H-isochromen-1-yl]-N-[(1S,2S)-2-hydroxy-2,3-dihydro-1H-inden-1-yl]acetamide into its molecular formula.
user
C20H21NO3
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