class Solution:
# @param {string} s
# @return {boolean}
def isValid(self, s):
Length = len(s)
List = []
for i in range(Length):
if s[i] == '(' or s[i] == '[' or s[i] == '{':
List.append(s[i])
if s[i] == ')':
if List == [] or List.pop() != '(': return False
if s[i] == ']':
if List == [] or List.pop() != '[': return False
if s[i] == '}':
if List == [] or List.pop() != '{': return False
if List: return False
else: return True