You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2R)-2-amino-N-spiro[2-oxabicyclo[3.2.0]heptane-7,1'-cyclobutane]-6-ylpropanamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C12H20N2O2
assistant