{-# LANGUAGE BangPatterns #-}

zeta :: Int -> Int -> Double
zeta a x = (\d -> 1.0 / (fromIntegral d)) $ last $ takeWhile (<= 1000000000000) $ take (x - 1) $ iterate ((* a)) (a - 1)

main :: IO ()
main = do
  x <- readLn :: IO Int
  if x == 2 then putStrLn "1000000"
  else print $ floor $ (* 1000000) $ sum $ map (\a -> zeta a x) [2..1000000]