You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3,6,6-trimethyl-4-oxo-N-(2-pyridin-2-ylsulfanylpyridin-4-yl)-5,7-dihydro-1-benzofuran-2-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C22H21N3O3S
assistant