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 n;
  cin >> n;
  int c = 0;
  for (int i = 2; i <= n; i++) {
    for (int j = 1; j <= n; j++) {
      if (i % j == 0)
        if (i * j > n)
          if (i / j < n) {
            cout << i << " " << j;
            c = 1;
            break;
          }
    }
    if (c == 1) break;
  }
  if (c == 0) cout << -1;
}