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, a = 1, b = 1;
  cin >> x;
  int flag = 0;
  for (int i = 1; i <= x; i++) {
    b = i;
    for (int j = 1; j <= i; j++) {
      a = j;
      if (b > (x / a)) {
        if (b > (a / x)) {
          if (b % a == 0) {
            flag = 1;
            break;
          }
        }
      }
    }
  }
  if (flag == 1)
    cout << b << " " << a;
  else
    cout << -1;
  return 0;
}