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(3, 6) :
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
3
6
1
0
0
1
1
6
↔
3
0
1
1
0
3
3
6
4
3
2
2
3
↔
3
3
2
1
0
0
3
3
↔
3
3
2
1
0
0
4
3
↔
3
3
2
1
0
0
5
3
↔
3
3
2
1
0
0
6
3
↔
3
3
2
1
0
0
7
3
3
1
0
3
2
0
(1)(3) - (0)(6) = 3