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, 5) :
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
14
5
1
0
0
1
1
14
5
1
0
0
1
9
7
6
14
3
7
2
7
5
3
7
0
1
2
0
3
8
3
8
1
8
22
4
11
3
1
5
4
11
0
1
4
1
4
12
4
12
2
Even
Even
2
6
4
2
↔
1
2
6
4
11
1
1
Even
Even
1
3
5
1
↔
1
1
3
4
11
0
6
1
↔
1
1
3
4
11
0
7
1
1
4
11
1
3
0
(4)(14) - (11)(5) = 1