You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-N,1-N,2-N,2-N-tetrakis(2-sulfido-1,3,2-dioxaphosphinan-2-ium-2-yl)benzene-1,2-diamine is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H28N2O8P4S4
assistant