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 ethyl (E,4S)-4-[[(2S,3S)-2-[(2,2-diethyl-4-methylhexanoyl)amino]-3-methylpentanoyl]-methylamino]-2,5-dimethylhex-2-enoate .
user
C28H52N2O4
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