MAIN	START
BEGIN	XOR	GR2,GR2
LOOP	CPA	GR2,LEN
    JZE LAST
    JPL	LAST
	LD	GR1,A,GR2
    XOR	GR1,GR1
    LAD	GR2,1,GR2
    JUMP LOOP
LAST RET
A	DC	#8001,#8000,#FFFF,#51,#7FFF
LEN	DC	5
	END