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 2-[(4S)-4-ethyl-4-(4-fluorophenyl)-2,5-dioxoimidazolidin-1-yl]-N-[(2R)-5-methylhexan-2-yl]acetamide .
user
C20H28FN3O3
assistant