factorization :: Int -> [(Int, Int)]
factorization n =
  if c > 0 then iter 3 m [(2, c)] else iter 3 n []
  where
    (c, m) = factor n 2 0
    factor n m c =
      if n `mod` m /= 0 then (c, n)
      else factor (n `div` m) m (c + 1)
    iter i n a
      | n == 1    = reverse a
      | n < i * i = reverse ((n, 1) : a)
      | otherwise =
          let (c, m) = factor n i 0
          in if c == 0 then iter (i + 2) n a
             else iter (i + 2) m ((i, c):a)

divisor_num :: Int -> Int
divisor_num n = foldl (\a (_, x) -> a * (x + 1)) 1 (factorization n)

solve :: Int -> Int
solve a
 | a == 1    = 1
 | otherwise = divisor_num a

main = do
 n <- read <$> getLine :: IO Int
 print $ sum $ map (solve) [1..(n-1)]
