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;
long long MOD = 1e9 + 7;
long long fastmod(long long x, long long n, long long mod = 1e9 + 7) {
  long long res = 1;
  while (n > 0) {
    if (n & 1) res = res * x % mod;
    x = x * x % mod;
    n >>= 1;
  }
  return res;
}
set<int> getdv(int k) {
  set<int> re;
  for (int i = 1; i <= sqrt(k); i++)
    if (k % i == 0) {
      re.insert(i);
      re.insert(k / i);
    }
  return re;
}
vector<pair<long long, long long> > vp;
int main() {
  int x;
  cin >> x;
  int a, b;
  for (int i = 1; i <= x; i++)
    for (int j = 1; j <= x; j++) {
      if (i > j) continue;
      if (j % i == 0 && i * j > x && j / i < x) {
        cout << j << " " << i << endl;
        return 0;
      }
    }
  cout << -1 << endl;
}