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 5-[prop-2-ynyl-[1-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)pyrrolidin-3-yl]amino]pyrazine-2-carbonitrile .
user
C18H16N8
assistant