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;
vector<bool> prime(1001, true);
void sieve() {
  prime[0] = false;
  prime[1] = false;
  for (int i = 2; i <= 1000; i++) {
    if (prime[i]) {
      int j = 2;
      while (i * j <= 1000) {
        prime[i * j] = false;
        j++;
      }
    }
  }
}
long long int ceil_sqrt(long long int a) {
  long long int i = 1;
  while (i * i < a) i++;
  return i;
}
void solve() {
  int x;
  cin >> x;
  if (x == 1) {
    cout << -1 << endl;
    return;
  }
  cout << (x / 2 + 1) << " " << (x / 2 + 1) << endl;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  solve();
  return 0;
}