Problem: Given an integer x, find 2 integers a and b such that: 

  * 1 ≤ a,b ≤ x 
  * b divides a (a is divisible by b). 
  * a ⋅ b>x. 
  * a/b<x. 

Input

The only line contains the integer x (1 ≤ x ≤ 100).

Output

You should output two integers a and b, satisfying the given conditions, separated by a space. If no pair of integers satisfy the conditions above, print "-1" (without quotes).

Examples

Input

10


Output

6 3

Input

1


Output

-1

Solution (in CPP):

Solution:
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using pli = pair<ll, int>;
using pil = pair<int, ll>;
template <typename T>
using Array = vector<T>;
template <typename T>
using Matrix = Array<Array<T>>;
using Graph = Matrix<int>;
template <typename T>
bool relax(T& r, const T& first) {
  if (first < r) {
    r = first;
    return true;
  }
  return false;
}
template <typename T>
bool heavy(T& h, const T& first) {
  if (h < first) {
    h = first;
    return true;
  }
  return false;
}
const int DX[8] = {-1, +1, +0, +0, +1, -1, +1, -1};
const int DY[8] = {+0, +0, -1, +1, +1, -1, -1, +1};
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  int first;
  cin >> first;
  for (int a = 1; a <= first; a++)
    for (int b = 1; b <= first; b++)
      if (a % b == 0 && a * b > first && a < b * first)
        cout << a << ' ' << b, exit(0);
  cout << -1;
  return false;
}