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 x, a, b;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cin >> x;
  for (int a = 1; a <= 100; a++) {
    for (int b = 1; b <= 100; b++) {
      if (a <= x && b <= x)
        if (a % b == 0)
          if (a * b > x)
            if (a / b < x) {
              cout << a << " " << b;
              return 0;
            }
    }
  }
  cout << "-1";
}