You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[4-[4-[(2-thiophen-2-yl-5,6,7,8-tetrahydro-[1]benzothiolo[2,3-d]pyrimidin-4-yl)oxy]phenyl]piperazin-1-yl]ethanone is the IUPAC name of a molecule. Please give its molecular formula.
user
C26H26N4O2S2
assistant