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 n;
bool k = false;
int main() {
  cin >> n;
  for (int i = 2; i <= n / 2 + 1; i++) {
    for (int j = i; j <= n; j += i) {
      if (i * j > n && j / i < n) {
        cout << j << " " << i << endl;
        k = true;
        break;
      }
    }
    if (k) {
      break;
    }
  }
  if (!k) {
    cout << -1 << endl;
  }
  return 0;
}