You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[(2S)-1-hydroxy-3-octadecanoyloxypropan-2-yl] (5E,7Z,11Z,14Z)-9-hydroxyicosa-5,7,11,14-tetraenoate is the IUPAC name of a molecule. Please give its molecular formula.
user
C41H72O6
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