def ask_pair_of_radii() -> (int, int):
    input_ok = False
    while not input_ok:
        try:
            r1 = int(input("r1 = "))
            r2 = int(input("r2 = "))
            input_ok = True
            return r1, r2
        except ValueError as ex:
            print("Eingabe ist keine Zahl")




def main():
    outer_radius, inner_radius = ask_pair_of_radii()
    print(f"Außenradius = {outer_radius} Innenradius =  {inner_radius}")


if __name__ == "__main__":
    main()