Z
9
x Z
7
isomorphic to Z
63
Z
9
x Z
7
isomorphic to Z
63
0
1
2
3
4
5
6
7
8
0
1
29
57
22
50
15
43
8
36
1
37
2
30
58
23
51
16
44
9
2
10
38
3
31
59
24
52
17
45
3
46
11
39
4
32
60
25
53
18
4
19
47
12
40
5
33
61
26
54
5
55
20
48
13
41
6
34
62
27
6
28
56
21
49
14
42
7
35
63
(5,3) -> 60
Reference: I. Niven, H. S. Zuckerman and H.L. Montgomery, An Introduction to the Theory of Numbers, p. 68.