You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[2-(2,5-dimethyl-1-propan-2-ylpyrrol-3-yl)-2-oxoethyl] 2-(2-pyridin-3-yl-1,3-thiazol-4-yl)acetate is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H23N3O3S
assistant