output_description: Print the maximum possible sum of the digits (in base 10) of a positive
  integer not greater than N.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N
attempt: n = list(input())
  x = []
  for i in n:
      x.append(int(i))
  out = int(n[0]) - 1 + (len(n) - 1) * 9
  sample = [1]
  sample.extend([9] * (len(n) - 1))
  if [9] * len(n) == x or sample == x or len(n) == 1:
      out = sum(x)
  print(out)
  
problem_description: Statement
  
  Find the maximum possible sum of the digits (in base 10) of a positive integer
  not greater than N.
samples: [{"input": "100", "output": "18\n    \n\nFor example, the sum of the digits in 99 is 18, which turns out to be the\nmaximum value.\n\n* * *"}, {"input": "9995", "output": "35\n    \n\nFor example, the sum of the digits in 9989 is 35, which turns out to be the\nmaximum value.\n\n* * *"}, {"input": "3141592653589793", "output": "137"}]