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 (3S,4S)-4-methyl-9-(7-methylpurin-2-yl)-1-oxa-9-azaspiro[5.5]undecane-3,4-diol is given. What is its corresponding molecular formula?
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C16H23N5O3
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