You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[(2S)-1-[(1-cyanocyclohexyl)-methylamino]-1-oxopropan-2-yl] 4-propan-2-yloxybenzoate is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H28N2O4
assistant