output_description: Print the answer.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N
attempt: # -*- coding: utf-8 -*-
  """
  Created on Sun Jan 19 21:23:54 2020
  
  @author: over-
  """
  
  N = input()
  L = len(N)
  
  c = 0
  for i in range(1, int(N) + 1):
      x = int(str(i)[0])
      y = int(str(i)[-1])
  
      if x == y:
  
          if L == 1:
              d = 1
          if L == 2:
              d = 1
              if int(N) >= int("{}{}".format(x, x)):
                  d += 1
          if L == 3:
              d = 1 + 1
              if int(N) >= int("{}9{}".format(x, x)):
                  d += 10
              elif int(N) >= int("{}0{}".format(x, x)):
                  d += int(N[1:-1]) + 1
          if L == 4:
              d = 1 + 1 + 10
              if int(N) >= int("{}99{}".format(x, x)):
                  d += 100
              elif int(N) >= int("{}00{}".format(x, x)):
                  d += int(N[1:-1]) + 1
          if L == 5:
              d = 1 + 1 + 10 + 100
              if int(N) >= int("{}999{}".format(x, x)):
                  d += 1000
              elif int(N) >= int("{}000{}".format(x, x)):
                  d += int(N[1:-1]) + 1
          if L == 6:
              d = 1 + 1 + 10 + 100 + 1000
              if int(N) >= int("{}9999{}".format(x, x)):
                  d += 10000
              elif int(N) >= int("{}0000{}".format(x, x)):
                  d += int(N[1:-1]) + 1
  
          c += d
      else:
          if y != 0:
              if L == 2:
                  d = 0
                  if int(N) >= int("{}{}".format(y, x)):
                      d += 1
              if L == 3:
                  d = 1
                  if int(N) >= int("{}9{}".format(y, x)):
                      d += 10
                  elif int(N) >= int("{}0{}".format(y, x)):
                      d += int(N[1:-1]) + 1
              if L == 4:
                  d = 1 + 10
                  if int(N) >= int("{}99{}".format(y, x)):
                      d += 100
                  elif int(N) > int("{}00{}".format(y, x)):
                      d += int(N[1:-1]) + 1
              if L == 5:
                  d = 1 + 10 + 100
                  if int(N) >= int("{}999{}".format(y, x)):
                      d += 1000
                  elif int(N) >= int("{}000{}".format(y, x)):
                      d += int(N[1:-1]) + 1
              if L == 6:
                  d = 1 + 10 + 100 + 1000
                  if int(N) >= int("{}9999{}".format(y, x)):
                      d += 10000
                  elif int(N) >= int("{}0000{}".format(y, x)):
                      d += int(N[1:-1]) + 1
  
              c += d
  
  print(c)
  
problem_description: Statement
  
  Given is a positive integer N.  
  Find the number of pairs (A, B) of positive integers not greater than N that
  satisfy the following condition:
  
    * When A and B are written in base ten without leading zeros, the last digit of A is equal to the first digit of B, and the first digit of A is equal to the last digit of B.
samples: [{"input": "25", "output": "17\n    \n\nThe following 17 pairs satisfy the condition: (1,1), (1,11), (2,2), (2,22),\n(3,3), (4,4), (5,5), (6,6), (7,7), (8,8), (9,9), (11,1), (11,11), (12,21),\n(21,12), (22,2), and (22,22).\n\n* * *"}, {"input": "1", "output": "1\n    \n\n* * *"}, {"input": "100", "output": "108\n    \n\n* * *"}, {"input": "2020", "output": "40812\n    \n\n* * *"}, {"input": "200000", "output": "400000008"}]