import Data.Array.Unboxed
import Control.Applicative ((<*>))   -- cf JBwoVL
import Data.List (tails, inits)      --    stackoverflow.com/a/42150321/849891

ps = 2 : [n | (r:q:_, px) <- (zip . tails . (2:) . map (^2) <*> inits) ps,
              (n,True)    <- assocs (
                                accumArray (\_ _ -> False) True (r+1,q-1)
                 [(m,()) | p <- px, let s=(r+p)`div`p*p, m <- [s,s+p..q-1]] 
                                  :: UArray Int Bool )]

main = do (print $ ps !! 10000000)