You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule 1-N-[2-[(3-bromopyridin-2-yl)methylsulfanyl]ethyl]-2-(4-methylphenyl)sulfonyl-1-N'-prop-2-ynylethene-1,1-diamine .
user
C20H22BrN3O2S2
assistant