You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[(6-piperidin-1-ylpyridin-3-yl)methyl]-2-([1,2,4]triazolo[1,5-a]pyrimidin-2-yl)acetamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H21N7O
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