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(14, 14) → Twos = 1 → Ext-GCD(7, 7) :

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 7 7 1 0 0 1
1 7 7 1 0 0 1 0
2 7 7 1 0 0 1 0
3 7 7 1 0 0 1 0
4 7 7 1 0 0 1 0
5 7 7 1 0 0 1 0
6 7 7 1 0 0 1 0
7 7 7 1 0 0 1 0
(1)(14) - (0)(14) = 14