You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-(4-ethoxyphenyl)-2-(4-prop-2-enyl-5-sulfanylidene-1H-1,2,4-triazol-3-yl)acetamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C15H18N4O2S
assistant