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