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(15, 11) :

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 15 11 1 0 0 1
1 15 11 1 0 0 1 4 0 1 1 1 1 2 12 16 6 8
2 2 11 6 8 0 1 9 1 Even Even 3 4
3 1 11 3 4 0 1 10 1 3 5 3 5 5 14 20 7 10
4 5 1 7 10 3 4 4 0 10 14 10 14 2 Even Even 5 7
5 2 1 5 7 3 4 1 1 16 22 8 11
6 1 1 8 11 3 4 0
7 1 1 3 4 8 11 0
(3)(15) - (4)(11) = 1