import Data.List primes = 2:3:[x | i<-[1..], j<-[-1,1], let x = 6*i+j, isPrime x] where isPrime n = null [i | i<-takeWhile (\x -> x^2 <= n) primes, mod n i == 0] isPrime x = null [y | y<-[2..floor (sqrt (fromIntegral x))], mod y 6 /= 1, mod x y == 0] main = readLn >>= print . product . map (\fs -> if odd (length fs) then head fs else 1) . group . factorization factorization :: Integer -> [Integer] factorization n = unfoldr fact (n, primes) where q = (floor . sqrt . fromIntegral) n fact (n', pps@(p:ps)) | n' == 1 = Nothing | isPrime n' = Just (n',(1,pps)) | otherwise = let (d,m) = divMod n' p in if m==0 then Just (p,(d,pps)) else fact (n',ps)