import Data.List primes :: [Int] 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] factorization :: Integer -> [Integer] factorization n = unfoldr fact (n, primes) where q = (floor . sqrt . fromIntegral) n fact (n', pps@(p:ps)) | n' == 1 = Nothing | p > q = Just (n',(1,pps)) | otherwise = let (d,m) = divMod n' p' in if m==0 then Just (p',(d,pps)) else fact (n',ps) where p' = fromIntegral p main = do [n,k] <- map read . words <$> getLine print $ (div n) $ head $ (++[n]) $ dropWhile (< k) $ factorization n