You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the molecule 1-[3-(3,3-difluoropyrrolidin-1-yl)cyclobutyl]-2-[4-[2-(hydroxymethyl)-4-methyl-1,3-thiazol-5-yl]-1,3-thiazol-2-yl]ethanone ?
user
C18H21F2N3O2S2
assistant