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;
  int init = -1;
  scanf("%d", &x);
  if (x == 1) {
    printf("%d", init);
    return 0;
  }
  for (int i = x; i >= 1; i--) {
    for (int j = 1; j <= x; j++) {
      if (i % j == 0 && (i / j) < x) {
        cout << i << " " << j << endl;
        return 0;
      }
    }
  }
  return 0;
}