You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-hydroxy-3-(7-methoxy-1-benzofuran-2-carbonyl)-1-(4-methylphenyl)-2-(3-methylthiophen-2-yl)-2H-pyrrol-5-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C26H21NO5S
assistant