You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-[3-(4-ethoxyphenyl)-1,2,4-oxadiazol-5-yl]-2-(4-fluorophenyl)isoquinolin-1-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C25H18FN3O3
assistant