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 maxn = 1e5 + 10;
const int maxm = 1e6 + 10;
const long long INF = 0x3f3f3f3f;
const long long mod = 1e9 + 7;
const int maxblock = sqrt(maxn) + 10;
const double eps = 1e-8;
int x;
int check(int a, int b) {
  if (a / b >= x) return 0;
  if (a * b <= x) return 0;
  return 1;
}
int main() {
  cin >> x;
  for (int i = 1; i <= x; i++) {
    for (int j = i; j <= x; j += i) {
      if (check(j, i)) {
        cout << j << " " << i << endl;
        return 0;
      }
    }
  }
  cout << -1 << endl;
  return 0;
}