You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
methyl (9E,12E)-octadeca-9,12-dienoate;methyl (9E,12E,15E)-octadeca-9,12,15-trienoate;methyl (E)-octadec-9-enoate is the IUPAC name of a molecule. Please give its molecular formula.
user
C57H102O6
assistant