from collections import deque

class Solution:
    bracket_pairing = {
        '{': '}',
        '[': ']',
        '(': ')'
    }
    
    closing_brackets = tuple(bracket_pairing.values())
    
    def is_matching_pair(self, opening, closing):
        return self.bracket_pairing[opening] == closing
    
    def isValid(self, s: str) -> bool:
        stack = deque()
        
        for c in s:
            if c in self.closing_brackets:
                try:
                    last_char = stack.pop()
                except IndexError:
                    return False
                
                if not self.is_matching_pair(last_char, c):
                    return False
            else:
                stack.append(c)
        
        return len(stack) == 0