You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule 2-cyano-N-(3-cyano-6-methyl-4,5,6,7-tetrahydro-1-benzothiophen-2-yl)-3-(2-methoxyphenyl)prop-2-enamide .
user
C21H19N3O2S
assistant