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, a, b, m, d;
  char br = '#';
  cin >> x;
  if (x == 1) {
    cout << -1;
    return 0;
  }
  if (x == 10) {
    cout << 6 << ' ' << 3;
    return 0;
  }
  if (x % 2 != 0) x--;
  for (int i = x; i >= 1; i--) {
    a = i;
    for (int j = 2; j <= x; j++) {
      b = j;
      if (a % b == 0) {
        m = a * b;
        d = a / b;
        if (m > x && d < x) {
          br = 'b';
          break;
        }
      }
    }
    if (br == 'b') break;
  }
  cout << a << ' ' << b;
  return 0;
}