#include <bits/stdc++.h>
using namespace std;
int n;
int main() {
  cin >> n;
  if (n == 2) return cout << 2 << " " << 2, 0;
  if (n >= 3) {
    if ((n / 2) % 2 == 0)
      cout << (n / 2) + 2 << " " << 2;
    else
      cout << (n / 2) + 1 << " " << 2;
  } else
    cout << -1;
}
