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() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  int n;
  cin >> n;
  if (n == 1) {
    cout << "-1";
    return 0;
  }
  if (n == 2) {
    cout << n << " " << n;
    return 0;
  } else {
    for (int b = 1; b <= n; b++) {
      int a = b;
      while (a <= n) {
        if (a * b > n) {
          cout << a << " " << b;
          return 0;
        }
        a += b;
      }
    }
  }
}