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() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long int i, j, k, l, m, n, o, p, g = 0, mini, ans, a, b;
  cin >> k;
  long double jo;
  for (i = 1; i <= k; i++) {
    for (j = 1; j <= k; j++) {
      jo = (j * 1.00 / i);
      if (j % i == 0 && j * i > k && jo < k) {
        cout << j << " " << i << endl;
        goto ll;
      }
    }
  }
  cout << -1 << endl;
ll:;
}