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, 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
14
11
1
0
0
1
1
14
11
1
0
0
1
3
7
12
14
6
7
2
7
11
6
7
0
1
4
1
6
8
6
8
2
Even
Even
3
4
3
2
↔
7
3
4
6
7
5
1
14
18
7
9
4
1
↔
7
7
9
6
7
6
1
13
16
2
2
3
Even
Even
1
1
5
3
1
1
1
7
9
2
0
8
10
8
10
1
Even
Even
4
5
6
1
1
4
5
7
9
0
7
1
1
4
5
7
9
0
(4)(14) - (5)(11) = 1