You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
6-methyl-4-N-(5-methyl-1H-pyrazol-3-yl)-2-N-[(3-phenyl-2,3-dihydro-1,2-oxazol-5-yl)methyl]pyrimidine-2,4-diamine is the IUPAC name of a molecule. Please give its molecular formula.
user
C19H21N7O
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