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 main() {
  int n;
  cin >> n;
  int flag = 0, a, b;
  for (int i = 1; i <= n; i++) {
    for (int j = i; j <= n; j++) {
      if (flag) break;
      if (j % i == 0) {
        if (j * i > n && j / i < n) {
          flag = 1;
          cout << j << " " << i << endl;
        }
      }
    }
  }
  if (!flag) cout << -1 << endl;
  return 0;
}