X =	00	01	02	03	04	05	06	07	08	09	10	11	12	13	14	15
Y =	00	01	02	03	04	05	06	07	08	09	10	11	12	13	14	15
X ↔ Y

Ext-GCD(10, 8) → Twos = 1 → Ext-GCD(5, 4) :

i	GCD			Bezout				AOdd :						AEven :
	A	↔	B	ax	ay	bx	by	|A-B|	A↔B	Sx	Sy	ax ← Sx'	ay ← Sy'	A ← A/2	ax ← ax + Y	ay ← ay + X	ax ← ax/2	ay ← ay/2
0	5		4	1	0	0	1
1	4	↔	5	0	1	1	0	1						2	4	6	2	3
2	2	↔	5	2	3	1	0	3						1	6	8	3	4
3	1	↔	5	3	4	1	0	4	1	4	4	4	4	2	Even	Even	2	2
4	2		1	2	2	3	4	1						1	Even	Even	1	1
5	1		1	1	1	3	4	0
6	1		1	1	1	3	4	0
7	1		1	1	1	3	4	0
(1)(10) - (1)(8) = 2