new_contents: # Link: https://oj.leetcode.com/problems/valid-parentheses/
  class Solution:
      # @return a boolean
      def isValid(self, s):
          stack = []
          m = {
              '(': ')',
              '{': '}',
              '[': ']'
          }
          for c in s:
              if c == '(' or c == '{' or c == '[':
                  stack.append(c)
              else:
                  if len(stack) == 0:
                      return False
                  t = stack.pop()
                  if m.get(t, None) != c:
                      return False
          return len(stack) == 0
  
subject: Add valid-parenthese