main = getLine >>= print . solve . read . head . words

solve :: Int -> Int
solve n = div n $ foldl (\acc x -> if acc == n && mod n x == 0 then x else acc) n primes
	where
	primes = primes' [2..n] (sqrt $ fromIntegral n)
	primes' [] _ = []
	primes' (x : xs) mb
		| fromIntegral x < mb = x : primes' [y | y <- xs, mod y x /= 0] mb
		| otherwise = x : xs