a = gets.to_i
under = a%100
top = (a-under)/100
ans = "NA"
if (top <=12 && top >= 1) && (under <= 12 && under >= 1)
  ans = "AMBIGUOUS"
elsif under <= 12 && under >= 1
  ans = "YYMM"
elsif top <=12 && top >= 1
  ans = "MMYY"
end
puts(ans)