Input Format

The first line contains a positive integer $n$, the length of the string.

The next line contains a string $s$.

Output Format

Output one non-negative integer, the answer.

3
(()

2

2
()

2

Hint

This problem uses $\texttt{Subtask}$ scoring. You can get the score of a $\texttt{Subtask}$ only if you pass all test points in that $\texttt{Subtask}$.

For $100\%$ of the testdata, it is guaranteed that $1 \leq n \leq 10^6$.

Translated by ChatGPT 5