You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2R)-2-(3,4a,5,6,7,7a-hexahydro-2H-cyclopenta[b][1,4]oxazine-4-carbonylamino)-5-amino-5-oxopentanoic acid is the IUPAC name of a molecule. Please give its molecular formula.
user
C13H21N3O5
assistant