Description:
You are given a bracket sequence $$$s$$$ consisting of $$$n$$$ opening '(' and closing ')' brackets.
A regular bracket sequence is a bracket sequence that can be transformed into a correct arithmetic expression by inserting characters '1' and '+' between the original characters of the sequence. For example, bracket sequences "()()", "(())" are regular (the resulting expressions are: "(1)+(1)", "((1+1)+1)"), and ")(" and "(" are not.
You can change the type of some bracket $$$s_i$$$. It means that if $$$s_i = $$$ ')' then you can change it to '(' and vice versa.
Your task is to calculate the number of positions $$$i$$$ such that if you change the type of the $$$i$$$-th bracket, then the resulting bracket sequence becomes regular.
Input Format:
The first line of the input contains one integer $$$n$$$ ($$$1 \le n \le 10^6$$$) — the length of the bracket sequence.
The second line of the input contains the string $$$s$$$ consisting of $$$n$$$ opening '(' and closing ')' brackets.
Output Format:
Print one integer — the number of positions $$$i$$$ such that if you change the type of the $$$i$$$-th bracket, then the resulting bracket sequence becomes regular.
Note:
None