```#
# 
# @param s string字符串 
# @return bool布尔型
#
import collections
class Solution:
    def isValid(self , s ):
        # write code here
        brackets = [i for i in s]
        n = len(brackets)
        if n==0 or n%2 == 1:
            return False
        stack = []
        match = {"(":")", "[":"]", "{":"}"}
        left = match.keys()
        right = match.values()
        for n in s:
            if n in left:
                stack.append(n)
            elif n in right:
                if not stack:
                    return False
                curr = stack.pop()
                if curr in left:
                    if match[curr]!=n:
                        return False
                else:
                    return False
        if stack:
            return False
        else:
            return True