1
1-2
1-3
1-4
2
2-2
2-3
2-4
3
4
4-2
4-3
5
6
7
7-2
7-3
8
8-2
9
9-2
10
10-2
10-3
10-4
11
11-2
11-3
12
12-2
12-3
12-4
13
13-2
13-3
13-4
13-5
13-6
13-7
14
14-2
15
15-2
15-3
15-4
15-5
16
16-2
16-3
17
17-2
17-3
17-4
17-5
18
18-2
19
19-2
19-3
19-4
20
20-1
20-2
20-3
20-4