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Translate the chemical IUPAC name 2-[7-(4-chlorophenyl)-4,5,13-trimethyl-3-thia-1,8,11,12-tetrazatricyclo[8.3.0.02,6]trideca-2(6),4,7,10,12-pentaen-9-yl]acetaldehyde;methanol into its molecular formula.
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C20H21ClN4O2S
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