You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule 3-[(7R,9aS)-7-(pyridin-2-yloxymethyl)-1,3,4,6,7,8,9,9a-octahydropyrido[1,2-a]pyrazin-2-yl]-1,2-benzoxazole into molecular formula.
user
C21H24N4O2
assistant