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