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>
int x(int a) {
  if (a % 2 == 0)
    return a;
  else
    return a - 1;
}
int y(int a) {
  if (a % 2 == 0)
    return a / 2;
  else
    return (a - 1) / 2;
}
int main() {
  int t, a, b;
  scanf("%d", &t);
  if (t == 1) {
    printf("-1");
    return 0;
  } else if (t == 2 || t == 3) {
    printf("%d %d", t, t);
    return 0;
  } else {
    a = x(t);
    b = y(t);
    printf("%d %d", a, b);
  }
}