You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the molecule 2-amino-N-[2-[2-[3-[(2E,4Z)-hepta-2,4,6-trien-3-yl]oxyphenyl]pyrrolidin-1-yl]-2-oxoethyl]acetamide ?
user
C21H27N3O3
assistant