You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
5,7-dimethyl-N-propan-2-yl-N-(pyridin-3-ylmethyl)pyrazolo[1,5-a]pyrimidine-3-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H21N5O
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