You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule 2-[3-[1-acetyl-5-amino-3-(difluoromethyl)-2,6-dihydropyrazin-3-yl]-4-fluorophenyl]-1-[5-(difluoromethoxy)-3-methylpyridin-2-yl]ethanone ?
user
C22H21F5N4O3
assistant