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-(5-ethyl-2-fluorophenyl)-N-[[3-fluoro-1-(3-fluoropyridin-2-yl)cyclobutyl]methyl]-1,3,4-thiadiazol-2-amine .
user
C20H19F3N4S
assistant