You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(E)-3-(2,5-dimethoxyphenyl)-N-(furan-2-ylmethyl)-N-(thiophen-2-ylmethyl)prop-2-enamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H21NO4S
assistant