You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[(6S)-3-cyclopropyl-6,7-dihydro-5H-pyrrolo[2,1-c][1,2,4]triazol-6-yl]-9-ethyl-8-(2-methylpyrimidin-5-yl)purin-6-amine is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H22N10
assistant