You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-(1,3-benzothiazol-2-ylmethyl)-3-[(5-methyl-1,3,4-thiadiazol-2-yl)sulfanylmethyl]-1-benzofuran-2-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H16N4O2S3
assistant