new_contents: """Leetcode 91. Decode Ways
  Medium
  
  URL: https://leetcode.com/problems/decode-ways/
  
  A message containing letters from A-Z is being encoded to numbers using the
  following mapping:
  
  'A' -> 1
  'B' -> 2
  ...
  'Z' -> 26
  
  Given a non-empty string containing only digits, determine the total number of 
  ways to decode it.
  
  Example 1:
  Input: "12"
  Output: 2
  Explanation: It could be decoded as "AB" (1 2) or "L" (12).
  
  Example 2:
  Input: "226"
  Output: 3
  Explanation: It could be decoded as "BZ" (2 26), "VF" (22 6), or "BBF" (2 2 6).
  """
  
  class Solution(object):
      def numDecodings(self, s):
          """
          :type s: str
          :rtype: int
          """
          pass
  
  
  def main():
  	pass
  
  
  if __name__ == '__main__':
  	main()
  
subject: Add lc091_decode_ways.py