4
0 h 0
0 h 1
0 h 2
0 h 3
1 t 0
1 t 1
1 t 2
1 t 3
2 cx 0 1
2 cx 2 3
3 t 0
3 t 1
3 t 2
3 t 3
4 cx 0 2
4 cx 1 3
8 t 0
8 t 1
8 t 2
8 t 3
9 cx 0 1
9 cx 2 3
10 t 0
10 t 1
10 t 2
10 t 3
11 cx 0 2
11 cx 1 3
17 h 0
17 h 1
17 h 2
17 h 3
