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:
array = range(0, 100)
x = int(input())
if 1 <= x <= 100:
    k = False
    for i in range(x , 1, -1):
        a = i
        for b in range(a, 1, -1):
            if a/b in array and a/b < x and a*b > x:
                print (a, int(b))
                k = True
                break
        break
    if k == False:
        print (-1)