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.