You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
tert-butyl N-[2-[[2-[[1-(4-fluorophenyl)-2-methylpropyl]amino]-2-oxoethyl]-methylamino]propyl]carbamate is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H34FN3O3
assistant