You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-(1-methylindol-5-yl)-1-[4-(1,3-thiazol-2-yl)piperazin-1-yl]prop-2-yn-1-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H18N4OS
assistant