You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[4-[[4-(diethylamino)-6-methylpyrimidin-2-yl]amino]phenyl]-3,5-dimethyl-1,2-oxazole-4-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
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C21H26N6O2
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