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 N-(3-fluoropyridin-2-yl)-N-[2-methyl-2-[4-(2-propan-2-yloxyethyl)piperazin-1-yl]propyl]propanamide ?
user
C21H35FN4O2
assistant