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, 12) → Twos = 1 → Ext-GCD(5, 6) :

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		6	1	0	0	1
1	6	↔	5	0	1	1	0	1						3	6	6	3	3
2	3	↔	5	3	3	1	0	2	1	4	3	4	3	1	10	8	5	4
3	1		3	5	4	3	3	2	1	8	7	2	2	1	Even	Even	1	1
4	1	↔	1	1	1	5	4	0
5	1	↔	1	1	1	5	4	0
6	1	↔	1	1	1	5	4	0
7	1		1	5	4	1	1	0
(5)(10) - (4)(12) = 2