You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule (2S,8aS)-2-(tert-butylcarbamoylamino)-N-(2-pyridin-4-ylethyl)-2,3,5,6,7,8-hexahydro-1H-indolizine-8a-carboxamide ?
user
C21H33N5O2
assistant