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 3-[1-(4-amino-5-methylpyrimidin-2-yl)piperidin-3-yl]-4-phenyl-1H-1,2,4-triazol-5-one into molecular formula.
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C18H21N7O
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