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;
int main() {
  int n;
  while (scanf("%d", &n) == 1) {
    if (n == 1)
      printf("-1\n");
    else if (n == 2) {
      printf("2 2\n");
    } else if (n == 4)
      printf("4 2\n");
    else {
      int a, b;
      if (n % 2 == 0) {
        a = n - 2;
        b = 2;
      } else {
        a = n - 1;
        b = 2;
      }
      printf("%d %d\n", a, b);
    }
  }
  return 0;
}