You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
5-(1-propan-2-ylindazol-5-yl)-3-(1,2,3,4-tetrahydroisoquinolin-5-yl)-1,2,4-oxadiazole is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H21N5O
assistant