You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule N,N-dimethyl-2-[2-oxo-7-(thiophen-2-ylmethyl)-5,6,8,9-tetrahydropyrido[2,3-d]azepin-1-yl]acetamide ?
user
C18H23N3O2S
assistant