You just got a pogo stick. You stand on it and jump: the first jump moves you 1 unit, the second jump moves you 2 units, the third jump moves you 3 units, and every later jump is one unit longer than the one before it.
Each jump goes in exactly one of four directions: north (y increases), south (y decreases), east (x increases), or west (x decreases). You cannot skip a jump and you cannot shorten one.
You start at (0,0) on an infinite plane and want to land exactly on (X,Y). The target is never (0,0), and it can always be reached.