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;
  while (cin >> x) {
    bool ok = true;
    for (int i = 1; i <= x && ok; i++) {
      for (int j = i; j <= x && ok; j++) {
        if (i * j > x && float(j) / i < x && j % i == 0) {
          cout << j << " " << i << '\n';
          ok = false;
        }
      }
    }
    if (ok) {
      cout << -1 << '\n';
    }
  }
  return 0;
}