You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the molecule 2,13-dithiapentacyclo[12.8.0.03,12.04,9.016,21]docosa-1(22),3(12),4,6,8,10,14,16,18,20-decaene-5,8,10,15-tetrol ?
user
C20H12O4S2
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