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:
el = int(input())
def element(x):
    for a in range(2, x+1):
        for b in range(a, 0, -1): 
            if a % b == 0 and a*b > x and a/b < x:
                return str(a) + " " + str(b)
    return "-1"

print(element(el))