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 identified by 2-[5-(3-fluorophenyl)sulfanyl-4-propan-2-yl-1-(pyridin-4-ylmethyl)imidazol-2-yl]acetonitrile ?
user
C20H19FN4S
assistant