I had this problem too, because of a logic problem...
Test:
9 2
0
0
0
0
2 0
2 0
6 0
6 0
8 0
10 6
1 2 3 4 5 6
11 3
7 8 9

Ans:
11 right
11 left
12 right
15 left
14 left
12 left
13 right
13 left
14 right