You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name ethyl (2R,3R,4S)-6-cyano-2,3-bis(ethoxycarbonylamino)-3,4-dihydro-2H-pyran-4-carboxylate into its molecular formula.
user
C15H21N3O7
assistant