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system
Provide the molecular formula for the IUPAC named substance 1-[6-[[(4S,9aR)-4-methyl-3,4,6,7,9,9a-hexahydro-1H-pyrazino[2,1-c][1,4]oxazin-8-yl]sulfonyl]-2,3-dihydro-1,4-benzoxazin-4-yl]ethanone .
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C18H25N3O5S
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