You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
5-[[[(3aR,6aS)-5-hydroxy-1,2,3,3a,4,5,6,6a-octahydropentalen-2-yl]-methylamino]methyl]-1,2,4-oxadiazole-3-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C13H20N4O3
assistant