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 1-methyl-4-(8-methylsulfanylspiro[6,7-dihydro-5H-1-benzothiepine-2,3'-cyclobutene]-6-yl)piperazine ?
user
C19H26N2S2
assistant