You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance (2E,4Z)-N-(2-methoxy-6,7,8,9-tetrahydro-5H-pyrido[2,3-d]azepin-3-yl)-6-[(2R)-oxan-2-yl]hexa-2,4-diene-3-sulfonamide .
user
C21H31N3O4S
assistant