output_description: Print the specified string: `YYMM`, `MMYY`, `AMBIGUOUS` or `NA`.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      S
attempt: print("NA")
  
problem_description: Statement
  
  You have a digit sequence S of length 4. You are wondering which of the
  following formats S is in:
  
    * YYMM format: the last two digits of the year and the two-digit representation of the month (example: `01` for January), concatenated in this order
    * MMYY format: the two-digit representation of the month and the last two digits of the year, concatenated in this order
  
  If S is valid in only YYMM format, print `YYMM`; if S is valid in only MMYY
  format, print `MMYY`; if S is valid in both formats, print `AMBIGUOUS`; if S
  is valid in neither format, print `NA`.
samples: [{"input": "1905", "output": "YYMM\n    \n\nMay XX19 is a valid date, but 19 is not valid as a month. Thus, this string is\nonly valid in YYMM format.\n\n* * *"}, {"input": "0112", "output": "AMBIGUOUS\n    \n\nBoth December XX01 and January XX12 are valid dates. Thus, this string is\nvalid in both formats.\n\n* * *"}, {"input": "1700", "output": "NA\n    \n\nNeither 0 nor 17 is valid as a month. Thus, this string is valid in neither\nformat."}]