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(4, 5) :

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