You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[2-[2-[[2-[2-(2-aminoethoxy)ethoxy]acetyl]amino]ethoxy]ethoxy]-N-[(5S)-5-(methylamino)-6-oxoheptyl]acetamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H40N4O7
assistant