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 a, b, x;
  cin >> x;
  if (x < 2)
    cout << -1 << endl;
  else {
    if (x % 2 == 0) {
      cout << x << " " << 2 << endl;
    } else {
      cout << x - 1 << " " << 2 << endl;
    }
  }
  return 0;
}