# 1249 Minimum Remove to Make Valid Parentheses

Given a string s of `'('` , `')'` and lowercase English characters.

Your task is to remove the minimum number of parentheses ( `'('` or `')'`, in any positions ) so that the resulting parentheses string is valid and return any valid string.

Formally, a parentheses string is valid if and only if:

• It is the empty string, contains only lowercase characters, or
• 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.

Example 1:

``````Input: s = "lee(t(c)o)de)"
Output: "lee(t(c)o)de"
Explanation: "lee(t(co)de)" , "lee(t(c)ode)" would also be accepted.
``````

Example 2:

``````Input: s = "a)b(c)d"
Output: "ab(c)d"
``````

Example 3:

``````Input: s = "))(("
Output: ""
Explanation: An empty string is also valid.
``````

Constraints:

• `1 <= s.length <= 105`
• `s[i]` is either`'('` , `')'`, or lowercase English letter.
 `````` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 `````` ``````class Solution: def minRemoveToMakeValid(self, s: str) -> str: stack=[] arr = list(s) for i in range(len(s)): if s[i] == '(': stack.append(i) elif s[i] == ')': if stack: stack.pop() else: arr[i] = "" for i in stack: arr[i] = "" return '' .join(arr)``````