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() {
  int n, a, b, i, j;
  scanf("%d", &a);
  if (a == 1)
    printf("-1\n");
  else {
    if (a % 2 == 0)
      printf("%d 2\n", a);
    else
      printf("%d 2\n", a - 1);
  }
  return 0;
}