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 JAVA):

Solution:
function main(n){

    for(var i = 1 ; i <= n ; i++){
      for(var j = 1 ; j <= n ; j++){
        if(((i%j === 0) || (j%i === 0)) && (i*j > n) && ((i/j) < n) && (i === j)){
          if(i > j){
            print(i + " " + j);
          }
          else print(j + " " + i);

          return;
        }
      }
    }
    print("-1");

}

var n = parseInt(readline());

main(n);