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 x;
  scanf("%d", &x);
  int i, j, flag = 1;
  for (i = 1; i <= x; i++) {
    for (j = x; i * j > x; j--)
      if (j % i == 0 && j / i < x) {
        printf("%d %d\n", j, i);
        flag = 0;
        break;
      }
    if (!flag) break;
  }
  if (flag) printf("-1\n");
  return 0;
}