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;
const int N = 105, M = 25;
int x, a, b;
bool t;
int main() {
  cin >> x;
  for (int i = 1; i <= x; i++) {
    for (int j = 1; j <= x; j++) {
      if (j % i == 0 && (i * j > x) && (j / i < x)) {
        t = 1;
        cout << j << " " << i << endl;
        break;
      }
    }
    if (t) break;
  }
  if (!t) cout << -1 << endl;
  return 0;
}