You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
phenyl N-[[(1R,2S,4R,5S,6S,7S)-7-hept-2-enyl-3,8-dioxatricyclo[3.2.1.02,4]octan-6-yl]methylamino]carbamate is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H28N2O4
assistant