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;
  while (cin >> n) {
    int z = 1;
    for (int i = 1; i <= n; i++) {
      int x = i;
      for (int j = 1; j <= i; j++) {
        int y = j;
        if (x * y > n && x % y == 0 && x / y < n) {
          cout << x << ' ' << y << endl;
          z = 0;
          break;
        }
      }
      if (!z) break;
    }
    if (z) cout << -1 << endl;
  }
}