You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[5-(4-fluorophenyl)-4-oxo-2-pyridin-3-ylthieno[2,3-d]pyrimidin-3-yl]acetic acid The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H12FN3O3S
assistant