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 PYTHON3):

Solution:
import math as m


def brute_force(x):
    for b in range(1, x + 1):
        for a in range(b, x + 1):
            if (a % b == 0 and a*b > x and a/b < x):
                print('{} {}'.format(a, b))
                return # to list all results, this return can be omitted


def better_search(x):
    for b in range(m.floor(m.sqrt(x)), x + 1):
        for a in range(b, x + 1, b):
            if (a*b > x and a/b < x):
                print('{} {}'.format(a, b))
                return # to list all results, this return can be omitted


def trivial(x):
        print('{} {}'.format(x, x))


if __name__ == '__main__':
    x = int(input())
    if x == 1:
        print('-1')
    else:
        # trivial(x)
        brute_force(x)
        #better_search(x)