1 0
2 0
3 0
4 [4, 14]
4 1
5 [4, 14]
5 1
6 [4, 14]
6 1
7 [4, 14]
7 1
8 [4, 14]
8 1
9 [4, 14]
9 1
10 [4, 14]
10 1
11 [11, 13]
11 [4, 14]
11 2
12 [11, 13]
12 [4, 14]
12 [12, 20]
12 3
13 [11, 13]
13 [4, 14]
13 [12, 20]
13 3
14 [4, 14]
14 [12, 20]
14 2
15 [15, 19]
15 [12, 20]
15 2
16 [15, 19]
16 [12, 20]
16 2
17 [15, 19]
17 [12, 20]
17 2
18 [18, 20]
18 [15, 19]
18 [12, 20]
18 3
19 [18, 20]
19 [15, 19]
19 [12, 20]
19 3
3