You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-(2-fluorophenyl)-2-[2-[[(1S)-1-(2-methoxy-5-methylphenyl)ethyl]amino]-2-oxoethyl]sulfanylacetamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H23FN2O3S
assistant