You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-[6-[(6-iodoimidazo[4,5-b]pyridin-3-yl)methyl]-8-methoxy-3,4-dihydro-2H-chromen-2-yl]-2-methyl-1,3-thiazole is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H19IN4O2S
assistant