You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2S)-2-[[(1R)-3,4-dihydro-1H-isochromene-1-carbonyl]amino]-3-(6-fluoro-1H-indol-3-yl)propanoic acid is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H19FN2O4
assistant