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 n;
int tab[1000007];
int main() {
  scanf("%d", &n);
  for (int b = 1; b <= n; b++) {
    for (int a = b; a <= n; a++) {
      if (a % b == 0) {
        if (a * b > n) {
          if (a / b < n) {
            printf("%d %d\n", a, b);
            return 0;
          }
        }
      }
    }
  }
  printf("-1\n");
  return 0;
}