921. 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