code: def filter_only_significant(word):
      
      if not word:
          return word
      # Unwrap a complete parenthesis.
      if word.startswith(u'(') and word.endswith(u')'):
          return filter_only_significant(word[1:-1])
      x = len(word)
      while x > 0:
          x -= 1
          c = word[x]
          # Skip a complete parenthesis.
          if c == u')':
              m = INSIGNIFICANT_PARENTHESIS_PATTERN.search(word[:x + 1])
              if m is not None:
                  x = m.start()
              continue
          # Skip unreadable characters such as punctuations.
          unicode_category = unicodedata.category(c)
          if not SIGNIFICANT_UNICODE_CATEGORY_PATTERN.match(unicode_category):
              continue
          break
      return word[:x + 1]
docs: Gets a word which removes insignificant letters at the end of the given
      word::
  
      >>> pick_significant(u'넥슨(코리아)')
      넥슨
      >>> pick_significant(u'메이플스토리...')
      메이플스토리