You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2R)-1-[(3R)-4-ethyl-3-(1-methylimidazol-2-yl)piperazin-1-yl]-2-thiophen-2-ylpropan-1-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C17H24N4OS
assistant