You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[2-[[2-(dimethylamino)-2-oxoethyl]amino]-2-oxoethyl] 2-(5,6-dimethyl-4-oxothieno[2,3-d]pyrimidin-3-yl)acetate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C16H20N4O5S
assistant