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 N'-ethyl-N-[1-(5-fluoro-2-methylphenyl)sulfanylethenyl]-N'-[1-(3-phenyl-2H-azaphosphol-4-yl)ethenyl]butane-1,4-diamine .
user
C26H31FN3PS
assistant