You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule [7-[(6-methylpyridin-2-yl)methyl]-6,8-dihydro-5H-imidazo[1,2-a]pyrazin-3-yl]-pyrrolidin-1-ylmethanone .
user
C18H23N5O
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