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;
int dx[] = {1, -1, 0, 0, 1, 1, -1, -1};
int dy[] = {0, 0, 1, -1, 1, -1, 1, -1};
void dance() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
}
void file() {
  freopen(".in", "r", stdin);
  freopen(".out", "w", stdout);
}
long long gcd(long long a, long long b) { return !b ? a : gcd(b, a % b); }
long long lcm(long long a, long long b) { return a / gcd(a, b) * b; }
template <typename t>
void printV(vector<t> v) {
  for (int i = 0; i < v.size(); i++) {
    cout << v[i] << ' ';
  }
  cout << endl;
}
bool isPrime(int n) {
  if (n == 2) return true;
  if (n < 2 || n % 2 == 0) return false;
  for (int i = 3; i * i <= n; i += 2)
    if (n % i == 0) return false;
  return true;
}
int main() {
  int x;
  cin >> x;
  for (int j = 1; j <= x; j++)
    for (int i = 1; i <= x; i++) {
      int a = i, b = j;
      if (a % b == 0 && a * b > x && a / b < x)
        return cout << a << ' ' << b << endl, 0;
    }
  cout << -1;
  return 0;
}