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;
using DO = double;
using INT = long long;
using pii = pair<int, int>;
using pi3 = pair<pii, int>;
int power(int a, int b, int mod, int ans = 1) {
  for (; b; b >>= 1, a = 1LL * a * a % mod)
    if (b & 1) ans = 1LL * ans * a % mod;
  return ans;
}
int main() {
  int n;
  cin >> n;
  for (int a = 1; a <= 10000; a++)
    for (int b = 1; b <= 10000; b++)
      if (a % b == 0 and a / b < n and a * b > n) {
        cout << a << ' ' << b << endl;
        return 0;
      }
  cout << -1 << endl;
  return 0;
}