You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-(2-cyclopropyl-2-hydroxyethyl)-2-(5-fluoro-2-methyl-1H-indol-3-yl)-N-methylacetamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C17H21FN2O2
assistant