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;
int power(int x, unsigned int y) {
  int temp;
  if (y == 0) return 1;
  temp = power(x, y / 2);
  if (y % 2 == 0)
    return temp * temp;
  else
    return x * temp * temp;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int n;
  pair<int, int> res;
  cin >> n;
  bool f = false;
  for (int b = 1; b <= n; b++) {
    for (int a = b; a <= n; a++) {
      if (a % b == 0 && a * b > n && a / b < n) {
        res = make_pair(a, b);
        f = true;
      }
    }
  }
  if (f)
    cout << res.first << " " << res.second << endl;
  else
    cout << -1 << endl;
  return 0;
}