You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[2-[[2-[(2-amino-3-hydroxypropanoyl)amino]-3-methylpentanoyl]amino]-3-methylpentanoyl]pyrrolidine-2-carboxylic acid The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H36N4O6
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