A pair of integers is written on a blackboard. At each step, we are allowed to erase the pair of numbers
(m, n) from the board and replace it with one of the following pairs: (n, m), (m − n, n), (m + n, n). If we
start with (2022, 315) written on the blackboard, then can we eventually have the pair
(a) (30, 45),
(b) (222, 15)?