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 div[2001];
  for (int j = 0, i = 1; i <= n; j++, i++) {
    div[j] = i;
  }
  for (int t = 0; t < n; t++) {
    for (int j = 0; j < n; j++) {
      if (div[t] * div[j] > n) {
        if ((div[t] % div[j] == 0) && (div[t] % div[j] < n)) {
          cout << div[t] << " " << div[j];
          return 0;
        }
      }
    }
  }
  cout << -1;
  return 0;
}