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-[4-[[9-[(3,4-difluorophenyl)methyl]-2,9-diazaspiro[4.5]decan-2-yl]methyl]thiophen-2-yl]ethanone ?
user
C22H26F2N2OS
assistant