3
3-4-5
1-2-3
2-5-6
2
6-7
4-5
7-8
10-11
8-9
9-12
12-13
13-14
13-14-17
12-15-16
15-16-19
18-19-20
17-18-19
20-21-22
21-24-25
22-23-24
23-26-27
21-24-26
26-27-28
25-26-29
28-29-30
21-26
17-22
23-28
13-17
19-22
21-27
6-12
4-8
9-13
14-18