You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-ethyl-N-[2-(ethylamino)-2-oxoethyl]-4-fluoro-3-methyl-1-benzothiophene-2-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C16H19FN2O2S
assistant