Question
Count Balanced Parentheses Substrings

You are given a string s of length n consisting only of characters '(' and ')'. Your task is to count the number of substrings that form a balanced parentheses sequence.

A substring is considered balanced if:

  • Every opening parenthesis has a corresponding closing parenthesis.
  • The parentheses are properly nested.
Input
The first line contains a single integer KaTeX can only parse string typed expression — the length of the string.
The second line contains a string KaTeX can only parse string typed expression of length KaTeX can only parse string typed expression, consisting only of '(' and ')'.
Output
Print a single integer — the number of substrings of KaTeX can only parse string typed expression that are balanced parentheses sequences.
Example
Input
6
(()())

Output
4

Explanation
Valid balanced substrings are:

() → from index 1 to 2
() → from index 3 to 4
()() → from index 1 to 4
(()()) → from index 0 to 5

Total = 4 substrings.

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