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 5-[[2-(4-aminophenyl)-4-morpholin-4-ylthieno[3,2-d]pyrimidin-6-yl]amino]-N-hydroxypyrazine-2-carboxamide is given. What is its corresponding molecular formula?
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C21H20N8O3S
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