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>
long long power(long long a, long long b, long long c) {
  long long ans = 1;
  a = (a % c);
  while (b > 0) {
    if (b & 1) {
      ans = (ans * a) % c;
    }
    b = b >> 1;
    a = (a * a) % c;
  }
  return ans;
}
long long sum4(int n) {
  long long sum = 0;
  while (n > 0) {
    sum += n % 10;
    n /= 10;
  }
  return sum;
}
using namespace std;
int main() {
  long long n;
  cin >> n;
  if (n == 1)
    cout << -1;
  else if (n % 2 == 0) {
    cout << n << " " << 2;
  } else {
    cout << n - 1 << " " << 2;
  }
}