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(7, 10) :
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
10
1
0
0
1
1
10
↔
7
0
1
1
0
3
5
10
8
5
4
2
5
↔
7
5
4
1
0
2
1
6
4
6
4
1
Even
Even
3
2
3
1
5
3
2
5
4
4
1
8
6
8
6
2
Even
Even
4
3
4
2
↔
1
4
3
3
2
1
1
14
10
7
5
5
1
↔
1
7
5
3
2
0
6
1
↔
1
7
5
3
2
0
7
1
1
3
2
7
5
0
(3)(7) - (2)(10) = 1