You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named 4-phenyl-8-(2-propan-2-yloxyethylsulfanyl)-4,5,7,9-tetrazatricyclo[7.5.0.02,6]tetradeca-1,5,7-trien-3-one by IUPAC nomenclature, provide its molecular formula.
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C21H26N4O2S
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