You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[4-[2-(1-ethylimidazol-4-yl)thieno[3,2-b]pyridin-7-yl]oxy-3-fluorophenyl]-N'-[2-(trifluoromethyl)phenyl]propanediamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C28H21F4N5O3S
assistant