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(12, 3) :

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 12 3 1 0 0 1
1 12 3 1 0 0 1 9 6 4 12 2 6
2 6 3 2 6 0 1 3 3 Even Even 1 3
3 3 3 1 3 0 1 0
4 3 3 1 3 0 1 0
5 3 3 1 3 0 1 0
6 3 3 1 3 0 1 0
7 3 3 1 3 0 1 0
(1)(12) - (3)(3) = 3