You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the molecule 4-[(2S)-2-[[5-chloro-4-oxo-3-(pyridin-2-ylmethyl)pyrrolo[2,1-f][1,2,4]triazin-2-yl]-sulfanylmethyl]azetidin-1-yl]-7H-pyrrolo[2,3-d]pyrimidine-5-carbonitrile ?
user
C23H18ClN9OS
assistant