minimum-add-to-make-parentheses-valid

A parentheses string is valid if and only if:

• It is the empty string,


• It can be written as AB (A concatenated with B), where A and B are valid strings, or


• It can be written as (A), where A is a valid string.

You are given a parentheses string s. In one move, you can insert a parenthesis at any position of the string.

• For example, if s = "()))", you can insert an opening parenthesis to be "(()))" or a closing parenthesis to be "())))".

Return the minimum number of moves required to make s valid.

Example 1:

Input: s = "())"
Output: 1

Example 2:

Input: s = "((("
Output: 3

Constraints:

• 1 <= s.length <= 1000


• s[i] is either '(' or ')'.