You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Convert the IUPAC name of a molecule 7-(4-aminobut-1-ynyl)-N-(1,2,3,4-tetrahydronaphthalen-1-yl)pyrido[3,2-d]pyrimidin-4-amine into molecular formula.
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C21H21N5
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