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;
vector<int> divisors[103];
void divisor() {
  for (int k = 1; k < 101; k++) {
    for (int i = 1; i < 101 / k; i++) divisors[i * k].push_back(k);
  }
}
int main() {
  int x, flag = 0, a, b;
  divisor();
  cin >> x;
  for (int i = x; i >= 1 && !flag; i--) {
    for (int j = 0; j < divisors[i].size(); j++) {
      if (i * divisors[i][j] > x && i / divisors[i][j] < x) {
        flag = 1;
        a = i;
        b = divisors[i][j];
        break;
      }
    }
  }
  if (flag)
    cout << a << " " << b << endl;
  else
    cout << "-1" << endl;
}