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 4-(2-chloropyridin-4-yl)-1-ethyl-6-phenylpyrazolo[3,4-b]pyridine-5-carboxylic acid is given. What is its corresponding molecular formula?
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C20H15ClN4O2
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