You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-[[(3S)-3-(3-cyclopentylprop-1-en-2-ylamino)-4-methylpent-1-en-2-yl]amino]hexan-2-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H36N2O
assistant