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system
Provide the molecular formula for the IUPAC named substance (1R,3R,3aS,6aR)-5-(4-ethylphenyl)-1-propan-2-ylspiro[1,2,3a,6a-tetrahydropyrrolo[3,4-c]pyrrole-3,6'-indolo[2,1-b]quinazoline]-4,6,12'-trione .
user
C31H28N4O3
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