Sorry for asking here, since I can't find the information on usaco website.

Specifically, it's for this problem (http://www.usaco.org/index.php?page=viewproblem2&cpid=194#). My submission got accepted on usaco judge (https://ideone.com/dRl8T2) but fails on the following test cases

1 2
()
Correct: 1
Mine: 0

1 6
()(())
Correct: 4
Mine: 2

In general, my code should've failed on test cases where there exist concurrently balanced brackets starting at index 0.