You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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N,N-dimethyl-5-[[5-[(E)-2-(3-methyl-2H-indazol-5-yl)ethenyl]pyrazin-2-yl]amino]pyridine-3-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
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C22H21N7O
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