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 Nod(int a, int b) {
  while (a && b) {
    if (a > b) {
      a = a % b;
    } else {
      b = b % a;
    }
  }
  return a | b;
}
int main() {
  ios_base::sync_with_stdio(false), cin.tie(NULL);
  int a;
  cin >> a;
  for (int i = 2; i <= a; i++) {
    if (a % i == 0) {
      cout << a << " " << i;
      return 0;
    }
  }
  cout << -1;
  return 0;
}