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:
def cal(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:
                return [a, b]
    return [-1]
y = int(input())
c = cal(y)
if len(c) > 1:
    print(c[0], c[1])
else:
    print(c[0])