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 a[1000];
  int x;
  cin >> x;
  for (int i = 1, j = 0; i <= x; i++, j++) {
    a[j] = i;
  }
  for (int i = 0; i < x; i++) {
    for (int j = 0; j < x; j++) {
      if (a[i] * a[j] > x && (a[i] % a[j] == 0) && (a[i] % a[j] < x)) {
        cout << a[i] << " " << a[j] << endl;
        exit(0);
      }
    }
  }
  cout << -1 << endl;
  return 0;
}