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(13, 15) :

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	13		15	1	0	0	1
1	13		15	1	0	0	1	2	1	1	1	1	1	1	16	14	8	7
2	1	↔	13	8	7	1	0	12	1	9	7	9	7	6	24	20	12	10
3	6		1	12	10	8	7	5						3	Even	Even	6	5
4	3		1	6	5	8	7	2	0	14	12	14	12	1	Even	Even	7	6
5	1		1	7	6	8	7	0
6	1		1	7	6	8	7	0
7	1		1	7	6	8	7	0
(7)(13) - (6)(15) = 1