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>
int main(void) {
  int a, b, x, decision = 0;
  scanf("%d", &x);
  for (b = 1; b <= x; b++) {
    for (a = b; a <= x; a++) {
      if ((a * b) > x && !(a % b) && (a / b) < x) {
        decision = 1;
        break;
      }
    }
    if (decision == 1) break;
  }
  if (decision)
    printf("%d %d", a, b);
  else
    printf("%d", -1);
  return 0;
}