new_contents: class Solution:
      # @return a string
  
      def countAndSay(self, n):
          res = '1'
          for _ in xrange(n-1):
              tmp = []
              for k, g in itertools.groupby(res):
                  tmp.append(str(len(list(g)))+k)
              res = ''.join(tmp)
          return res
  
subject: add solution for Count and Say