You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-chloro-5-(5-fluoropyrimidin-2-yl)-N-[2-(2-formyl-1,3-thiazol-5-yl)-2-morpholin-4-ylethyl]benzamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H19ClFN5O3S
assistant