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;
void speed() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
}
int main() {
  speed();
  int n;
  cin >> n;
  for (int g = 1, k = 1; g <= n, k <= n; k++, g++) {
    if (g % k == 0 && g * k > n && g / k < n) {
      cout << g << " " << k << endl;
      return 0;
    }
  }
  cout << -1 << endl;
  return 0;
}