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

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