A valid parentheses string is either empty `""`, `"(" + A + ")"`, or `A + B`, where `A` and `B` are valid parentheses strings, and `+` represents string concatenation.

- For example, `""`, `"()"`, `"(())()"`, and `"(()(()))"` are all valid parentheses strings.

A valid parentheses string `s` is primitive if it is nonempty, and there does not exist a way to split it into `s = A + B`, with `A` and `B` nonempty valid parentheses strings.

Given a valid parentheses string `s`, consider its primitive decomposition: `s = P1 + P2 + ... + Pk`, where `Pi` are primitive valid parentheses strings.

Return `s` after removing the outermost parentheses of every primitive string in the primitive decomposition of `s`.

Example 1:

    Input: s = "(()())(())"
    Output: "()()()"
    Explanation:
    The input string is "(()())(())", with primitive decomposition "(()())" + "(())".
    After removing outer parentheses of each part, this is "()()" + "()" = "()()()".

Example 2:

    Input: s = "(()())(())(()(()))"
    Output: "()()()()(())"
    Explanation:
    The input string is "(()())(())(()(()))", with primitive decomposition "(()())" + "(())" + "(()(()))".
    After removing outer parentheses of each part, this is "()()" + "()" + "()(())" = "()()()()(())".

Example 3:

    Input: s = "()()"
    Output: ""
    Explanation:
    The input string is "()()", with primitive decomposition "()" + "()".
    After removing outer parentheses of each part, this is "" + "" = "".

Constraints:

- `1 <= s.length <= 105`
- `s[i]` is either `'('` or `')'`.
- `s` is a valid parentheses string.