text: K = int(input())
  
  flg = False
  ans = 0
  for a in range(1, K**2+1):
      for b in range(a, K**2+1):
          c = K//(a*b)
  
          if a == b:
              ans += c
          else:
              ans += c*2
  
          if c == 0:
              flg = True
              break
      if flg:
          flg = False
          if K < a*2+1:
              break
  
  
  print(ans)
  