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 n, a, b;
int main() {
  while (cin >> n) {
    a = 0, b = 0;
    for (int i = 1; i <= n; i++) {
      for (int j = 1; j <= n; j++) {
        if (j % i) continue;
        if (i * j <= n) continue;
        if ((double)(i / j) >= n) continue;
        a = j, b = j;
        break;
      }
    }
    if (a == 0 && b == 0)
      cout << -1 << endl;
    else
      cout << a << " " << b << endl;
  }
  return 0;
}