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 N-[(6S)-3-(3-cyclopropyl-1,2,4-oxadiazol-5-yl)-6-ethyl-4,5,6,7-tetrahydro-1-benzothiophen-2-yl]cyclopentene-1-carboxamide .
user
C21H25N3O2S
assistant