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