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) {
    int flag = 0;
    for (int i = x; i >= 1; i--) {
      for (int j = i; j >= 1; j--) {
        if (i % j == 0) {
          if (i * j > x && i / j < x) {
            cout << i << " " << j << endl;
            flag = 1;
            break;
          }
        }
      }
      if (flag == 1) break;
    }
    if (!flag) cout << -1 << endl;
  }
}