You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2S)-2-[[(2R,3R)-3-[(2S)-1-[4-[[2-[[2-[4-aminobutyl(methyl)amino]-3-methylbutanoyl]amino]acetyl]-methylamino]-3-methoxy-5-methylheptanoyl]pyrrolidin-2-yl]-3-methoxy-2-methylpropanoyl]amino]-3-phenylpropanoic acid is the IUPAC name of a molecule. Please give its molecular formula.
user
C40H68N6O8
assistant