You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
tert-butyl 3-[3-[(1R)-1-(tert-butylsulfanylamino)ethyl]-5-(hydroxymethyl)phenyl]-3-fluoroazetidine-1-carboxylate is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H33FN2O3S
assistant