{-# LANGUAGE PatternGuards #-}
 
import Data.List
import Data.Function
 
tsieve (x:xs) = x : tsieve [y | y <- xs, rem y x /= 0]
 
psieve (p:ps) xs | (h,t) <- span (< p*p) xs = 
             h ++ psieve ps [y | y <- t, rem y p /= 0]
 
main = do { n <- fmap read getLine ;
  print . 
    last . take n . -- nubBy (((==0).).rem) $ [2..]
                    -- tsieve $ [2..]
                    -- fix $ (2:) . (`psieve` [3..])
                       (`psieve` [2..]) . fix $ (2:) . (`psieve` [3..])
  }

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

100000

nubBy (((==0).).rem) [2..] --  2k 0.79s  5.8 MB  --   4k 3.51s  5.8 MB  --  n^2.15
T-sieve:                   --  4k 0.62s  6.8 MB  --   8k 2.98s  6.8 MB  --  n^2.25
postponed T-sieve          -- 40k 0.57s 10.9 MB  -- 100k 1.88s 12.9 MB  --  n^1.30
staged postp'd T-sv        -- 40k 0.46s  8.8 MB  -- 400k 10.52  8.9 MB  --  n^1.36