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 unsigned long long int MOD = 1000000007;
const long double PI = 2 * acos(0.0);
vector<long long int> ga(long long int n) {
  vector<long long int> a;
  for (long long int i = 0; i < n; i++) {
    long long int p;
    cin >> p;
    a.push_back(p);
  }
  return a;
}
vector<unsigned long long int> gau(unsigned long long int n) {
  vector<unsigned long long int> a;
  for (unsigned long long int i = 0; i < n; i++) {
    unsigned long long int p;
    cin >> p;
    a.push_back(p);
  }
  return a;
}
vector<string> gas(unsigned long long int n) {
  vector<string> a;
  for (unsigned long long int i = 0; i < n; i++) {
    string p;
    cin >> p;
    a.push_back(p);
  }
  return a;
}
template <typename T, typename A>
void pa(vector<T, A> const &a) {
  for (T p : a) {
    cout << p << " ";
  }
  cout << endl;
}
int main(void) {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long int x;
  cin >> x;
  long long int k = x - 1;
  long long int b = 2;
  if (x == 1)
    cout << "-1";
  else
    cout << x << " " << x;
  return 0;
}