open System

let if' b f =
  if b then Some (f ()) else None

let factorize (n: int64): Map<int64, int> =
  let rec count p n =
      if n % p <> 0L
      then (n, 0)
      else count p (n / p) |> (fun (m, k) -> (m, k + 1))

  let f (p, n) =
      if' (n <> 1L) (fun () ->
        if p * p <= n then
          let (n', k) = count p n
          let elem = if' (k > 0) (fun () -> (p, k))
          (elem, (p + 1L, n'))
        else
          (Some (n, 1), (p, 1L))
        )

  Seq.unfold f (2L, n) |> Seq.choose id |> Map.ofSeq

let solve n =
  factorize n
  |> Map.toSeq
  |> Seq.choose (fun (k, v) -> if v % 2 <> 0 then Some k else None)
  |> Seq.fold (*) 1L

[<EntryPoint>]
let main _ =
  let x = Console.ReadLine() |> int64
  //printfn "%A" (factorize x)
  printfn "%d" (solve x)

  //exit code
  0