You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
5-ethyl-2,3-dimethyl-7-[3-(4-methyl-1,2,4-triazol-3-yl)piperidin-1-yl]pyrazolo[1,5-a]pyrimidine The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H25N7
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