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, c, i, j;
  while (scanf("%d", &n) != EOF) {
    c = 0;
    for (i = n; i >= n; i--) {
      for (j = 1; j <= i; j++) {
        if (i % j == 0 && i * j > n && i / j < n) {
          a = i;
          b = j;
          c = 1;
          break;
        }
      }
      if (c == 1) break;
    }
    if (c == 1)
      printf("%d %d\n", a, b);
    else
      printf("-1\n");
  }
  return 0;
}