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 PYTHON):

Solution:
def suites(a, b, x):
    return (
        1 <= b <= a
        and a <= b <= x
        and a % b == 0
        and a * b > x
        and a / b < x
    )


def find_solution(x):
    for i in range(1, x + 1):
        for j in range(1, x + 1):
            if suites(i, j, x):
                return i, j

    return None, None


x = int(raw_input())
a, b = find_solution(x)
if a is None:
    print(-1)
else:
    print a, b