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;
long long int min(long long int a, long long int b) {
  if (a > b)
    return b;
  else
    return a;
}
long long int max(long long int a, long long int b) {
  if (a > b)
    return a;
  else
    return b;
}
int main() {
  int x;
  cin >> x;
  int savea, saveb;
  int a, b;
  int flag = 0;
  for (b = 1; b <= x; b++) {
    for (a = b; a <= x; a++) {
      int k = a / b;
      if ((a * b) > x && k * b == a && k < x) {
        flag = 1;
        savea = a;
        saveb = b;
        break;
      }
    }
    if (flag == 1) break;
  }
  if (flag == 1) {
    cout << savea << " " << saveb;
  } else
    cout << "-1";
  return 0;
}