1, 1
2, 2
3, 1
4, 2
4, 1
3, 2
2, 1
1, 2
5, 1
6, 2
7, 1
8, 2
8, 1
7, 2
6, 1
5, 2
9, 1
10, 2
10, 1
9, 2
11, 1
12, 2
12, 1
11, 2
13, 1
13, 2
14, 1
14, 2