You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Under IUPAC nomenclature, a molecule named (6R,9S)-2-methyl-6,9-diphenyl-5,6,7,9-tetrahydro-4H-[1,2,4]triazolo[5,1-b]quinazolin-8-one is given. What is its corresponding molecular formula?
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C22H20N4O
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