output_description: Print the minimum possible value of "the sum of the digits of A" plus "the sum
  of the digits of B".
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N
attempt: N = int(input())
  ls = []
  for i in range(1, N - 1):
      b = N - i
      e = i % 10
      f = i % 100
      g = i % 1000
      h = i % 10000
      j = i % 100000
      E = b % 10
      F = b % 100
      G = b % 1000
      H = b % 10000
      J = b % 100000
      x = e + (f - e) / 10 + (g - f) / 100 + (h - g) / 1000 + (j - h) / 10000
      X = E + (F - E) / 10 + (G - F) / 100 + (H - G) / 1000 + (J - H) / 10000
      ls.append(x + X)
  print(int(min(ls)))
  
problem_description: Statement
  
  Takahashi has two positive integers A and B.
  
  It is known that A plus B equals N. Find the minimum possible value of "the
  sum of the digits of A" plus "the sum of the digits of B" (in base 10).
samples: [{"input": "15", "output": "6\n    \n\nWhen A=2 and B=13, the sums of their digits are 2 and 4, which minimizes the\nvalue in question.\n\n* * *"}, {"input": "100000", "output": "10"}]