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(5, 4) :

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