You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[hydroxy-[(Z)-3-[(Z)-octadec-11-enoyl]oxy-2-[[(E)-triacont-21-enoyl]amino]octadec-4-enoxy]phosphoryl]oxyethyl-trimethylazanium is the IUPAC name of a molecule. Please give its molecular formula.
user
C71H138N2O7P+
assistant