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system
Name the molecular formula for the molecule established as 1-[(8S)-2-ethyl-5,6,7,8-tetrahydro-[1,2,4]triazolo[1,5-a]pyridin-8-yl]-3-[(1R)-4-hydroxy-2,3-dihydro-1H-inden-1-yl]urea using the IUPAC nomenclature.
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C18H23N5O2
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