#include <bits/stdc++.h>
using namespace std;
void numbers(int x) {
  if (x <= 1 || x > 100) {
    cout << -1 << endl;
  } else {
    int a = x, b = x;
    cout << a << " " << b << endl;
  }
}
int main() {
  int x;
  cin >> x;
  numbers(x);
  return 0;
}
