#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int a = floor(sqrt(n)) + 1;
  assert(a * a > n);
  if (n == 1) {
    cout << "-1\n";
  } else {
    cout << a << " " << a << "\n";
  }
  return 0;
}
