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;
const int MAX = 1000000;
int prime[MAX];
int pn = 0;
bool check[MAX + 1];
int gcd(int x, int y) {
  if (y == 0)
    return x;
  else
    return gcd(y, x % y);
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  int input;
  cin >> input;
  long long a = 1;
  int b = 1;
  while (1) {
    if (b > input) break;
    for (int j = 1; j <= b; j++) {
      if ((a % b == 0) && ((a * b) > input) && ((a / b) < input)) {
        return cout << a << " " << b, 0;
      }
    }
    a++;
    b++;
  }
  return cout << -1, 0;
}