# Find the longest sequence of multiple Parentheses

Problem statement: Given a string `s`

consisting of open and closed brackets `"("`

and `")"`

, return the length of the longest substring in `s`

that is a valid string of parentheses.

# Example 1

**Input**

`s = ")(())(()"`

**Output**

`4`

**Explanation**

`"(())"`

is the longest substring with valid parentheses.

**Naive approach:** Find all the substrings of a given string. For every string, check…