You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[6-fluoro-5-methoxy-2-methyl-4-(5-methylthiophene-2-carbonyl)-7H-indol-3-yl]acetic acid The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H16FNO4S
assistant