You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-(2-bicyclo[2.2.1]heptanyl)-4-(3-methyl-5-propan-2-ylpyridin-2-yl)piperazine The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H31N3
assistant