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 x;
  cin >> x;
  for (int b = 1; b <= x; b++) {
    for (int a = 1; a <= x; a++) {
      if (a * b <= x) continue;
      if (((double)a / (double)b) >= (double)x) continue;
      if (a % b != 0) continue;
      cout << a << " " << b << endl;
      return 0;
    }
  }
  cout << -1 << endl;
}