You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2S)-2-[[(2S)-2-(3-methoxy-2,5-dioxopyrrolidin-1-yl)-5-(phenylmethoxycarbonylamino)pentanoyl]amino]propanoic acid The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H27N3O8
assistant